diff --git a/analysis_options.yaml b/analysis_options.yaml
new file mode 100644
index 0000000..61b6c4d
--- /dev/null
+++ b/analysis_options.yaml
@@ -0,0 +1,29 @@
+# This file configures the analyzer, which statically analyzes Dart code to
+# check for errors, warnings, and lints.
+#
+# The issues identified by the analyzer are surfaced in the UI of Dart-enabled
+# IDEs (https://dart.dev/tools#ides-and-editors). The analyzer can also be
+# invoked from the command line by running `flutter analyze`.
+
+# The following line activates a set of recommended lints for Flutter apps,
+# packages, and plugins designed to encourage good coding practices.
+include: package:flutter_lints/flutter.yaml
+
+linter:
+  # The lint rules applied to this project can be customized in the
+  # section below to disable rules from the `package:flutter_lints/flutter.yaml`
+  # included above or to enable additional rules. A list of all available lints
+  # and their documentation is published at
+  # https://dart-lang.github.io/linter/lints/index.html.
+  #
+  # Instead of disabling a lint rule for the entire project in the
+  # section below, it can also be suppressed for a single line of code
+  # or a specific dart file by using the `// ignore: name_of_lint` and
+  # `// ignore_for_file: name_of_lint` syntax on the line or in the file
+  # producing the lint.
+  rules:
+    # avoid_print: false  # Uncomment to disable the `avoid_print` rule
+    # prefer_single_quotes: true  # Uncomment to enable the `prefer_single_quotes` rule
+
+# Additional information about this file can be found at
+# https://dart.dev/guides/language/analysis-options
diff --git a/android/.gitignore b/android/.gitignore
index bc2100d..6f56801 100644
--- a/android/.gitignore
+++ b/android/.gitignore
@@ -5,3 +5,9 @@ gradle-wrapper.jar
 /gradlew.bat
 /local.properties
 GeneratedPluginRegistrant.java
+
+# Remember to never publicly share your keystore.
+# See https://flutter.dev/docs/deployment/android#reference-the-keystore-from-the-app
+key.properties
+**/*.keystore
+**/*.jks
diff --git a/android/app/build.gradle b/android/app/build.gradle
index 56fdea7..e504d38 100644
--- a/android/app/build.gradle
+++ b/android/app/build.gradle
@@ -26,24 +26,28 @@ apply plugin: 'kotlin-android'
 apply from: "$flutterRoot/packages/flutter_tools/gradle/flutter.gradle"
 
 android {
-    compileSdkVersion 28
+    compileSdkVersion flutter.compileSdkVersion
 
-    sourceSets {
-        main.java.srcDirs += 'src/main/kotlin'
+    compileOptions {
+        sourceCompatibility JavaVersion.VERSION_1_8
+        targetCompatibility JavaVersion.VERSION_1_8
+    }
+
+    kotlinOptions {
+        jvmTarget = '1.8'
     }
 
-    lintOptions {
-        disable 'InvalidPackage'
+    sourceSets {
+        main.java.srcDirs += 'src/main/kotlin'
     }
 
     defaultConfig {
         // TODO: Specify your own unique Application ID (https://developer.android.com/studio/build/application-id.html).
         applicationId "com.example.doctor_booking_app"
-        minSdkVersion 16
-        targetSdkVersion 28
+        minSdkVersion flutter.minSdkVersion
+        targetSdkVersion flutter.targetSdkVersion
         versionCode flutterVersionCode.toInteger()
         versionName flutterVersionName
-        testInstrumentationRunner "androidx.test.runner.AndroidJUnitRunner"
     }
 
     buildTypes {
@@ -61,7 +65,4 @@ flutter {
 
 dependencies {
     implementation "org.jetbrains.kotlin:kotlin-stdlib-jdk7:$kotlin_version"
-    testImplementation 'junit:junit:4.12'
-    androidTestImplementation 'androidx.test:runner:1.1.1'
-    androidTestImplementation 'androidx.test.espresso:espresso-core:3.1.1'
 }
diff --git a/android/app/src/main/AndroidManifest.xml b/android/app/src/main/AndroidManifest.xml
index c5fbc8a..f264829 100644
--- a/android/app/src/main/AndroidManifest.xml
+++ b/android/app/src/main/AndroidManifest.xml
@@ -1,21 +1,25 @@
 <manifest xmlns:android="http://schemas.android.com/apk/res/android"
     package="com.example.doctor_booking_app">
-    <!-- io.flutter.app.FlutterApplication is an android.app.Application that
-         calls FlutterMain.startInitialization(this); in its onCreate method.
-         In most cases you can leave this as-is, but you if you want to provide
-         additional functionality it is fine to subclass or reimplement
-         FlutterApplication and put your custom class here. -->
-    <application
-        android:name="io.flutter.app.FlutterApplication"
+   <application
         android:label="doctor_booking_app"
+        android:name="${applicationName}"
         android:icon="@mipmap/ic_launcher">
         <activity
             android:name=".MainActivity"
+            android:exported="true"
             android:launchMode="singleTop"
             android:theme="@style/LaunchTheme"
             android:configChanges="orientation|keyboardHidden|keyboard|screenSize|smallestScreenSize|locale|layoutDirection|fontScale|screenLayout|density|uiMode"
             android:hardwareAccelerated="true"
             android:windowSoftInputMode="adjustResize">
+            <!-- Specifies an Android theme to apply to this Activity as soon as
+                 the Android process has started. This theme is visible to the user
+                 while the Flutter UI initializes. After that, this theme continues
+                 to determine the Window background behind the Flutter UI. -->
+            <meta-data
+              android:name="io.flutter.embedding.android.NormalTheme"
+              android:resource="@style/NormalTheme"
+              />
             <intent-filter>
                 <action android:name="android.intent.action.MAIN"/>
                 <category android:name="android.intent.category.LAUNCHER"/>
diff --git a/android/app/src/main/kotlin/com/example/doctor_booking_app/MainActivity.kt b/android/app/src/main/kotlin/com/example/doctor_booking_app/MainActivity.kt
index b5105d4..191fe3c 100644
--- a/android/app/src/main/kotlin/com/example/doctor_booking_app/MainActivity.kt
+++ b/android/app/src/main/kotlin/com/example/doctor_booking_app/MainActivity.kt
@@ -1,12 +1,6 @@
 package com.example.doctor_booking_app
 
-import androidx.annotation.NonNull;
 import io.flutter.embedding.android.FlutterActivity
-import io.flutter.embedding.engine.FlutterEngine
-import io.flutter.plugins.GeneratedPluginRegistrant
 
 class MainActivity: FlutterActivity() {
-    override fun configureFlutterEngine(@NonNull flutterEngine: FlutterEngine) {
-        GeneratedPluginRegistrant.registerWith(flutterEngine);
-    }
 }
diff --git a/android/app/src/main/res/drawable-v21/launch_background.xml b/android/app/src/main/res/drawable-v21/launch_background.xml
new file mode 100644
index 0000000..f74085f
--- /dev/null
+++ b/android/app/src/main/res/drawable-v21/launch_background.xml
@@ -0,0 +1,12 @@
+<?xml version="1.0" encoding="utf-8"?>
+<!-- Modify this file to customize your launch splash screen -->
+<layer-list xmlns:android="http://schemas.android.com/apk/res/android">
+    <item android:drawable="?android:colorBackground" />
+
+    <!-- You can insert your own image assets here -->
+    <!-- <item>
+        <bitmap
+            android:gravity="center"
+            android:src="@mipmap/launch_image" />
+    </item> -->
+</layer-list>
diff --git a/android/app/src/main/res/values-night/styles.xml b/android/app/src/main/res/values-night/styles.xml
new file mode 100644
index 0000000..3db14bb
--- /dev/null
+++ b/android/app/src/main/res/values-night/styles.xml
@@ -0,0 +1,18 @@
+<?xml version="1.0" encoding="utf-8"?>
+<resources>
+    <!-- Theme applied to the Android Window while the process is starting when the OS's Dark Mode setting is on -->
+    <style name="LaunchTheme" parent="@android:style/Theme.Black.NoTitleBar">
+        <!-- Show a splash screen on the activity. Automatically removed when
+             Flutter draws its first frame -->
+        <item name="android:windowBackground">@drawable/launch_background</item>
+    </style>
+    <!-- Theme applied to the Android Window as soon as the process has started.
+         This theme determines the color of the Android Window while your
+         Flutter UI initializes, as well as behind your Flutter UI while its
+         running.
+
+         This Theme is only used starting with V2 of Flutter's Android embedding. -->
+    <style name="NormalTheme" parent="@android:style/Theme.Black.NoTitleBar">
+        <item name="android:windowBackground">?android:colorBackground</item>
+    </style>
+</resources>
diff --git a/android/app/src/main/res/values/styles.xml b/android/app/src/main/res/values/styles.xml
index 00fa441..d460d1e 100644
--- a/android/app/src/main/res/values/styles.xml
+++ b/android/app/src/main/res/values/styles.xml
@@ -1,8 +1,18 @@
 <?xml version="1.0" encoding="utf-8"?>
 <resources>
-    <style name="LaunchTheme" parent="@android:style/Theme.Black.NoTitleBar">
+    <!-- Theme applied to the Android Window while the process is starting when the OS's Dark Mode setting is off -->
+    <style name="LaunchTheme" parent="@android:style/Theme.Light.NoTitleBar">
         <!-- Show a splash screen on the activity. Automatically removed when
              Flutter draws its first frame -->
         <item name="android:windowBackground">@drawable/launch_background</item>
     </style>
+    <!-- Theme applied to the Android Window as soon as the process has started.
+         This theme determines the color of the Android Window while your
+         Flutter UI initializes, as well as behind your Flutter UI while its
+         running.
+
+         This Theme is only used starting with V2 of Flutter's Android embedding. -->
+    <style name="NormalTheme" parent="@android:style/Theme.Light.NoTitleBar">
+        <item name="android:windowBackground">?android:colorBackground</item>
+    </style>
 </resources>
diff --git a/android/build.gradle b/android/build.gradle
index 3100ad2..4256f91 100644
--- a/android/build.gradle
+++ b/android/build.gradle
@@ -1,12 +1,12 @@
 buildscript {
-    ext.kotlin_version = '1.3.50'
+    ext.kotlin_version = '1.6.10'
     repositories {
         google()
-        jcenter()
+        mavenCentral()
     }
 
     dependencies {
-        classpath 'com.android.tools.build:gradle:3.5.0'
+        classpath 'com.android.tools.build:gradle:4.1.0'
         classpath "org.jetbrains.kotlin:kotlin-gradle-plugin:$kotlin_version"
     }
 }
@@ -14,7 +14,7 @@ buildscript {
 allprojects {
     repositories {
         google()
-        jcenter()
+        mavenCentral()
     }
 }
 
diff --git a/android/gradle.properties b/android/gradle.properties
index 38c8d45..94adc3a 100644
--- a/android/gradle.properties
+++ b/android/gradle.properties
@@ -1,4 +1,3 @@
 org.gradle.jvmargs=-Xmx1536M
-android.enableR8=true
 android.useAndroidX=true
 android.enableJetifier=true
diff --git a/android/gradle/wrapper/gradle-wrapper.properties b/android/gradle/wrapper/gradle-wrapper.properties
index 296b146..bc6a58a 100644
--- a/android/gradle/wrapper/gradle-wrapper.properties
+++ b/android/gradle/wrapper/gradle-wrapper.properties
@@ -3,4 +3,4 @@ distributionBase=GRADLE_USER_HOME
 distributionPath=wrapper/dists
 zipStoreBase=GRADLE_USER_HOME
 zipStorePath=wrapper/dists
-distributionUrl=https\://services.gradle.org/distributions/gradle-5.6.2-all.zip
+distributionUrl=https\://services.gradle.org/distributions/gradle-6.7-all.zip
diff --git a/android/settings.gradle b/android/settings.gradle
index 5a2f14f..44e62bc 100644
--- a/android/settings.gradle
+++ b/android/settings.gradle
@@ -1,15 +1,11 @@
 include ':app'
 
-def flutterProjectRoot = rootProject.projectDir.parentFile.toPath()
+def localPropertiesFile = new File(rootProject.projectDir, "local.properties")
+def properties = new Properties()
 
-def plugins = new Properties()
-def pluginsFile = new File(flutterProjectRoot.toFile(), '.flutter-plugins')
-if (pluginsFile.exists()) {
-    pluginsFile.withReader('UTF-8') { reader -> plugins.load(reader) }
-}
+assert localPropertiesFile.exists()
+localPropertiesFile.withReader("UTF-8") { reader -> properties.load(reader) }
 
-plugins.each { name, path ->
-    def pluginDirectory = flutterProjectRoot.resolve(path).resolve('android').toFile()
-    include ":$name"
-    project(":$name").projectDir = pluginDirectory
-}
+def flutterSdkPath = properties.getProperty("flutter.sdk")
+assert flutterSdkPath != null, "flutter.sdk not set in local.properties"
+apply from: "$flutterSdkPath/packages/flutter_tools/gradle/app_plugin_loader.gradle"
diff --git a/lib/data/data.dart b/lib/data/data.dart
index 913a980..426926c 100644
--- a/lib/data/data.dart
+++ b/lib/data/data.dart
@@ -1,9 +1,8 @@
 import 'package:doctor_booking_app/model/speciality.dart';
 import 'package:flutter/cupertino.dart';
 
-List<SpecialityModel> getSpeciality(){
-
-  List<SpecialityModel> specialities = new List<SpecialityModel>();
+List<SpecialityModel> getSpeciality() {
+  List<SpecialityModel> specialities = [];
   SpecialityModel specialityModel = new SpecialityModel();
 
   //1
@@ -34,4 +33,4 @@ List<SpecialityModel> getSpeciality(){
   specialityModel = new SpecialityModel();
 
   return specialities;
-}
\ No newline at end of file
+}
diff --git a/lib/model/speciality.dart b/lib/model/speciality.dart
index 56474fe..20c2fe6 100644
--- a/lib/model/speciality.dart
+++ b/lib/model/speciality.dart
@@ -2,9 +2,9 @@ import 'package:flutter/cupertino.dart';
 
 class SpecialityModel{
 
-  String imgAssetPath;
-  String speciality;
-  int noOfDoctors;
-  Color backgroundColor;
+  String? imgAssetPath;
+  String? speciality;
+  int? noOfDoctors;
+  Color? backgroundColor;
   SpecialityModel({this.imgAssetPath,this.speciality,this.noOfDoctors, this.backgroundColor});
 }
\ No newline at end of file
diff --git a/lib/views/doctor_info.dart b/lib/views/doctor_info.dart
index 52cad27..9882d51 100644
--- a/lib/views/doctor_info.dart
+++ b/lib/views/doctor_info.dart
@@ -1,4 +1,5 @@
 import 'package:flutter/material.dart';
+import 'package:flutter/services.dart';
 
 class DoctorsInfo extends StatefulWidget {
   @override
@@ -12,10 +13,11 @@ class _DoctorsInfoState extends State<DoctorsInfo> {
       appBar: AppBar(
         backgroundColor: Colors.transparent,
         elevation: 0.0,
-        brightness: Brightness.light,
-        iconTheme: IconThemeData(
-          color: Colors.black87
+        systemOverlayStyle: SystemUiOverlayStyle(
+          systemNavigationBarColor: Colors.blue, // Navigation bar
+          statusBarColor: Colors.red, // Status bar
         ),
+        iconTheme: IconThemeData(color: Colors.black87),
       ),
       body: SingleChildScrollView(
         child: Container(
@@ -108,7 +110,8 @@ class _DoctorsInfoState extends State<DoctorsInfo> {
                                 height: 3,
                               ),
                               Container(
-                                  width: MediaQuery.of(context).size.width - 268,
+                                  width:
+                                      MediaQuery.of(context).size.width - 268,
                                   child: Text(
                                     "House # 2, Road # 5, Green Road Dhanmondi, Dhaka, Bangladesh",
                                     style: TextStyle(color: Colors.grey),
@@ -139,7 +142,8 @@ class _DoctorsInfoState extends State<DoctorsInfo> {
                                 height: 3,
                               ),
                               Container(
-                                  width: MediaQuery.of(context).size.width - 268,
+                                  width:
+                                      MediaQuery.of(context).size.width - 268,
                                   child: Text(
                                     '''Monday - Friday
 Open till 7 Pm''',
@@ -171,7 +175,8 @@ Open till 7 Pm''',
                 children: <Widget>[
                   Expanded(
                     child: Container(
-                      padding: EdgeInsets.symmetric(vertical: 24,horizontal: 16),
+                      padding:
+                          EdgeInsets.symmetric(vertical: 24, horizontal: 16),
                       decoration: BoxDecoration(
                           color: Color(0xffFBB97C),
                           borderRadius: BorderRadius.circular(20)),
@@ -179,31 +184,33 @@ Open till 7 Pm''',
                         mainAxisAlignment: MainAxisAlignment.center,
                         children: <Widget>[
                           Container(
-                            padding: EdgeInsets.all(8),
-                            decoration: BoxDecoration(
-                              color: Color(0xffFCCA9B),
-                              borderRadius: BorderRadius.circular(16)
-                            ),
+                              padding: EdgeInsets.all(8),
+                              decoration: BoxDecoration(
+                                  color: Color(0xffFCCA9B),
+                                  borderRadius: BorderRadius.circular(16)),
                               child: Image.asset("assets/list.png")),
                           SizedBox(
                             width: 16,
                           ),
                           Container(
-                            width: MediaQuery.of(context).size.width/2 - 130,
+                            width: MediaQuery.of(context).size.width / 2 - 130,
                             child: Text(
                               "List Of Schedule",
-                              style: TextStyle(color: Colors.white,
-                              fontSize: 17),
+                              style:
+                                  TextStyle(color: Colors.white, fontSize: 17),
                             ),
                           )
                         ],
                       ),
                     ),
                   ),
-                  SizedBox(width: 16,),
+                  SizedBox(
+                    width: 16,
+                  ),
                   Expanded(
                     child: Container(
-                      padding: EdgeInsets.symmetric(vertical: 24,horizontal: 16),
+                      padding:
+                          EdgeInsets.symmetric(vertical: 24, horizontal: 16),
                       decoration: BoxDecoration(
                           color: Color(0xffA5A5A5),
                           borderRadius: BorderRadius.circular(20)),
@@ -214,18 +221,17 @@ Open till 7 Pm''',
                               padding: EdgeInsets.all(8),
                               decoration: BoxDecoration(
                                   color: Color(0xffBBBBBB),
-                                  borderRadius: BorderRadius.circular(16)
-                              ),
+                                  borderRadius: BorderRadius.circular(16)),
                               child: Image.asset("assets/list.png")),
                           SizedBox(
                             width: 16,
                           ),
                           Container(
-                            width: MediaQuery.of(context).size.width/2 - 130,
+                            width: MediaQuery.of(context).size.width / 2 - 130,
                             child: Text(
                               "Doctor's Daily Post",
-                              style: TextStyle(color: Colors.white,
-                                  fontSize: 17),
+                              style:
+                                  TextStyle(color: Colors.white, fontSize: 17),
                             ),
                           )
                         ],
@@ -243,8 +249,8 @@ Open till 7 Pm''',
 }
 
 class IconTile extends StatelessWidget {
-  final String imgAssetPath;
-  final Color backColor;
+  final String? imgAssetPath;
+  final Color? backColor;
 
   IconTile({this.imgAssetPath, this.backColor});
 
@@ -258,7 +264,7 @@ class IconTile extends StatelessWidget {
         decoration: BoxDecoration(
             color: backColor, borderRadius: BorderRadius.circular(15)),
         child: Image.asset(
-          imgAssetPath,
+          imgAssetPath!,
           width: 20,
         ),
       ),
diff --git a/lib/views/home.dart b/lib/views/home.dart
index 08e7b6e..45cd6fd 100644
--- a/lib/views/home.dart
+++ b/lib/views/home.dart
@@ -2,23 +2,22 @@ import 'package:doctor_booking_app/data/data.dart';
 import 'package:doctor_booking_app/model/speciality.dart';
 import 'package:doctor_booking_app/views/doctor_info.dart';
 import 'package:flutter/material.dart';
+import 'package:flutter/services.dart';
 
-String selectedCategorie= "Adults";
+String? selectedCategorie = "Adults";
 
 class HomePage extends StatefulWidget {
   @override
-  _HomePageState createState() => _HomePageState();
+  HomePageState createState() => HomePageState();
 }
 
-class _HomePageState extends State<HomePage> {
+class HomePageState extends State<HomePage> {
+  List<String> categories = ["Adults", "Childrens", "Womens", "Mens"];
 
-  List<String> categories = ["Adults","Childrens","Womens","Mens"];
-
-  List<SpecialityModel> specialities;
+  late List<SpecialityModel> specialities;
 
   @override
   void initState() {
-    // TODO: implement initState
     super.initState();
 
     specialities = getSpeciality();
@@ -30,69 +29,84 @@ class _HomePageState extends State<HomePage> {
       appBar: AppBar(
         backgroundColor: Colors.white,
         elevation: 0.0,
-        brightness: Brightness.light,
-        iconTheme: IconThemeData(
-            color: Colors.black87
+        systemOverlayStyle: SystemUiOverlayStyle(
+          systemNavigationBarColor: Colors.blue, // Navigation bar
+          statusBarColor: Colors.red, // Status bar
         ),
+        iconTheme: IconThemeData(color: Colors.black87),
       ),
-      drawer: Drawer(
-          child: Container()// Populate the Drawer in the next step.
-      ),
+      drawer: Drawer(child: Container() // Populate the Drawer in the next step.
+          ),
       body: SingleChildScrollView(
         child: Container(
           color: Colors.white,
-          padding: EdgeInsets.symmetric(vertical: 10,horizontal: 24),
+          padding: EdgeInsets.symmetric(vertical: 10, horizontal: 24),
           child: Column(
             crossAxisAlignment: CrossAxisAlignment.start,
             children: <Widget>[
-              SizedBox(height: 10,),
-              Text("Find Your \nConsultation", style: TextStyle(
-                color: Colors.black87.withOpacity(0.8),
-                fontSize: 30,
-                fontWeight: FontWeight.w600
-              ),),
-              SizedBox(height: 40,),
+              SizedBox(
+                height: 10,
+              ),
+              Text(
+                "Find Your \nConsultation",
+                style: TextStyle(
+                    color: Colors.black87.withOpacity(0.8),
+                    fontSize: 30,
+                    fontWeight: FontWeight.w600),
+              ),
+              SizedBox(
+                height: 40,
+              ),
               Container(
                 padding: EdgeInsets.symmetric(horizontal: 24),
                 height: 50,
                 decoration: BoxDecoration(
-                  color: Color(0xffEFEFEF),
-                  borderRadius: BorderRadius.circular(14)
-                ),
+                    color: Color(0xffEFEFEF),
+                    borderRadius: BorderRadius.circular(14)),
                 child: Row(
                   children: <Widget>[
                     Icon(Icons.search),
-                    SizedBox(width: 10,),
-                    Text("Search", style: TextStyle(
-                      color: Colors.grey,
-                      fontSize: 19
-                    ),)
+                    SizedBox(
+                      width: 10,
+                    ),
+                    Text(
+                      "Search",
+                      style: TextStyle(color: Colors.grey, fontSize: 19),
+                    )
                   ],
                 ),
               ),
-              SizedBox(height: 30,),
-              Text("Categories", style: TextStyle(
-                  color: Colors.black87.withOpacity(0.8),
-                  fontSize: 25,
-                  fontWeight: FontWeight.w600
-              ),),
-              SizedBox(height: 20,),
+              SizedBox(
+                height: 30,
+              ),
+              Text(
+                "Categories",
+                style: TextStyle(
+                    color: Colors.black87.withOpacity(0.8),
+                    fontSize: 25,
+                    fontWeight: FontWeight.w600),
+              ),
+              SizedBox(
+                height: 20,
+              ),
               Container(
                 height: 30,
                 child: ListView.builder(
-                itemCount: categories.length,
+                    itemCount: categories.length,
                     shrinkWrap: true,
                     physics: ClampingScrollPhysics(),
                     scrollDirection: Axis.horizontal,
-                    itemBuilder: (context, index){
-                  return CategorieTile(
-                    categorie: categories[index],
-                    isSelected: selectedCategorie == categories[index],
-                    context: this,
-                  );
+                    itemBuilder: (context, index) {
+                      return CategorieTile(
+                        categorie: categories[index],
+                        isSelected: selectedCategorie == categories[index],
+                        context: this,
+                      );
                     }),
               ),
-              SizedBox(height: 20,),
+              SizedBox(
+                height: 20,
+              ),
               Container(
                 height: 250,
                 child: ListView.builder(
@@ -100,7 +114,7 @@ class _HomePageState extends State<HomePage> {
                     shrinkWrap: true,
                     physics: ClampingScrollPhysics(),
                     scrollDirection: Axis.horizontal,
-                    itemBuilder: (context, index){
+                    itemBuilder: (context, index) {
                       return SpecialistTile(
                         imgAssetPath: specialities[index].imgAssetPath,
                         speciality: specialities[index].speciality,
@@ -109,13 +123,19 @@ class _HomePageState extends State<HomePage> {
                       );
                     }),
               ),
-              SizedBox(height: 20,),
-              Text("Doctos", style: TextStyle(
-                  color: Colors.black87.withOpacity(0.8),
-                  fontSize: 25,
-                  fontWeight: FontWeight.w600
-              ),),
-              SizedBox(height: 20,),
+              SizedBox(
+                height: 20,
+              ),
+              Text(
+                "Doctos",
+                style: TextStyle(
+                    color: Colors.black87.withOpacity(0.8),
+                    fontSize: 25,
+                    fontWeight: FontWeight.w600),
+              ),
+              SizedBox(
+                height: 20,
+              ),
               DoctorsTile()
             ],
           ),
@@ -126,11 +146,10 @@ class _HomePageState extends State<HomePage> {
 }
 
 class CategorieTile extends StatefulWidget {
-
-  final String categorie;
-  final bool isSelected;
-  _HomePageState context;
-  CategorieTile({this.categorie, this.isSelected,this.context});
+  final String? categorie;
+  final bool? isSelected;
+  final HomePageState? context;
+  CategorieTile({this.categorie, this.isSelected, this.context});
 
   @override
   _CategorieTileState createState() => _CategorieTileState();
@@ -140,8 +159,8 @@ class _CategorieTileState extends State<CategorieTile> {
   @override
   Widget build(BuildContext context) {
     return GestureDetector(
-      onTap: (){
-        widget.context.setState(() {
+      onTap: () {
+        widget.context!.setState(() {
           selectedCategorie = widget.categorie;
         });
       },
@@ -151,25 +170,29 @@ class _CategorieTileState extends State<CategorieTile> {
         margin: EdgeInsets.only(left: 8),
         height: 30,
         decoration: BoxDecoration(
-          color: widget.isSelected ? Color(0xffFFD0AA) : Colors.white,
-          borderRadius: BorderRadius.circular(30)
+            color: widget.isSelected! ? Color(0xffFFD0AA) : Colors.white,
+            borderRadius: BorderRadius.circular(30)),
+        child: Text(
+          widget.categorie!,
+          style: TextStyle(
+              color:
+                  widget.isSelected! ? Color(0xffFC9535) : Color(0xffA1A1A1)),
         ),
-        child: Text(widget.categorie, style: TextStyle(
-          color: widget.isSelected ?  Color(0xffFC9535) : Color(0xffA1A1A1)
-        ),),
       ),
     );
   }
 }
 
 class SpecialistTile extends StatelessWidget {
-
-  final String imgAssetPath;
-  final String speciality;
-  final int noOfDoctors;
-  final Color backColor;
-  SpecialistTile({@required this.imgAssetPath,@required this.speciality
-    ,@required this.noOfDoctors, @required this.backColor});
+  final String? imgAssetPath;
+  final String? speciality;
+  final int? noOfDoctors;
+  final Color? backColor;
+  SpecialistTile(
+      {required this.imgAssetPath,
+      required this.speciality,
+      required this.noOfDoctors,
+      required this.backColor});
 
   @override
   Widget build(BuildContext context) {
@@ -177,23 +200,27 @@ class SpecialistTile extends StatelessWidget {
       width: 150,
       margin: EdgeInsets.only(right: 16),
       decoration: BoxDecoration(
-        color: backColor,
-        borderRadius: BorderRadius.circular(24)
-      ),
-      padding: EdgeInsets.only(top: 16,right: 16,left: 16),
+          color: backColor, borderRadius: BorderRadius.circular(24)),
+      padding: EdgeInsets.only(top: 16, right: 16, left: 16),
       child: Column(
         crossAxisAlignment: CrossAxisAlignment.start,
         children: <Widget>[
-          Text(speciality, style: TextStyle(
-            color: Colors.white,
-            fontSize: 20
-          ),),
-          SizedBox(height: 6,),
-          Text("$noOfDoctors Doctors", style: TextStyle(
-            color: Colors.white,
-            fontSize: 13
-          ),),
-          Image.asset(imgAssetPath, height: 160,fit: BoxFit.fitHeight,)
+          Text(
+            speciality!,
+            style: TextStyle(color: Colors.white, fontSize: 20),
+          ),
+          SizedBox(
+            height: 6,
+          ),
+          Text(
+            "$noOfDoctors Doctors",
+            style: TextStyle(color: Colors.white, fontSize: 13),
+          ),
+          Image.asset(
+            imgAssetPath!,
+            height: 160,
+            fit: BoxFit.fitHeight,
+          )
         ],
       ),
     );
@@ -204,55 +231,56 @@ class DoctorsTile extends StatelessWidget {
   @override
   Widget build(BuildContext context) {
     return GestureDetector(
-      onTap: (){
-        Navigator.push(context, MaterialPageRoute(
-          builder: (context) => DoctorsInfo()
-        ));
+      onTap: () {
+        Navigator.push(
+            context, MaterialPageRoute(builder: (context) => DoctorsInfo()));
       },
       child: Container(
         decoration: BoxDecoration(
-          color: Color(0xffFFEEE0),
-          borderRadius: BorderRadius.circular(20)
-        ),
-        padding: EdgeInsets.symmetric(horizontal: 24,
-        vertical: 18),
+            color: Color(0xffFFEEE0), borderRadius: BorderRadius.circular(20)),
+        padding: EdgeInsets.symmetric(horizontal: 24, vertical: 18),
         child: Row(
           children: <Widget>[
-            Image.asset("assets/doctor_pic.png", height: 50,),
-            SizedBox(width: 17,),
+            Image.asset(
+              "assets/doctor_pic.png",
+              height: 50,
+            ),
+            SizedBox(
+              width: 17,
+            ),
             Column(
               crossAxisAlignment: CrossAxisAlignment.start,
               children: <Widget>[
-                Text("Dr. Stefeni Albert", style: TextStyle(
-                  color: Color(0xffFC9535),
-                  fontSize: 19
-                ),),
-                SizedBox(height: 2,),
-                Text("Heart Speailist", style: TextStyle(
-                  fontSize: 15
-                ),)
+                Text(
+                  "Dr. Stefeni Albert",
+                  style: TextStyle(color: Color(0xffFC9535), fontSize: 19),
+                ),
+                SizedBox(
+                  height: 2,
+                ),
+                Text(
+                  "Heart Speailist",
+                  style: TextStyle(fontSize: 15),
+                )
               ],
             ),
             Spacer(),
             Container(
-              padding: EdgeInsets.symmetric(horizontal: 15,
-              vertical: 9),
+              padding: EdgeInsets.symmetric(horizontal: 15, vertical: 9),
               decoration: BoxDecoration(
-                color: Color(0xffFBB97C),
-                borderRadius: BorderRadius.circular(13)
+                  color: Color(0xffFBB97C),
+                  borderRadius: BorderRadius.circular(13)),
+              child: Text(
+                "Call",
+                style: TextStyle(
+                    color: Colors.white,
+                    fontSize: 13,
+                    fontWeight: FontWeight.w500),
               ),
-              child: Text("Call", style: TextStyle(
-                color: Colors.white,
-                fontSize: 13,
-                fontWeight: FontWeight.w500
-              ),),
             )
           ],
         ),
       ),
-    ); 
+    );
   }
 }
-
-
-
diff --git a/pubspec.lock b/pubspec.lock
index fcf6763..22baa65 100644
--- a/pubspec.lock
+++ b/pubspec.lock
@@ -1,69 +1,62 @@
 # Generated by pub
 # See https://dart.dev/tools/pub/glossary#lockfile
 packages:
-  archive:
-    dependency: transitive
-    description:
-      name: archive
-      url: "https://pub.dartlang.org"
-    source: hosted
-    version: "2.0.11"
-  args:
-    dependency: transitive
-    description:
-      name: args
-      url: "https://pub.dartlang.org"
-    source: hosted
-    version: "1.5.2"
   async:
     dependency: transitive
     description:
       name: async
       url: "https://pub.dartlang.org"
     source: hosted
-    version: "2.4.0"
+    version: "2.8.2"
   boolean_selector:
     dependency: transitive
     description:
       name: boolean_selector
       url: "https://pub.dartlang.org"
     source: hosted
-    version: "1.0.5"
-  charcode:
+    version: "2.1.0"
+  characters:
     dependency: transitive
     description:
-      name: charcode
+      name: characters
       url: "https://pub.dartlang.org"
     source: hosted
-    version: "1.1.2"
-  collection:
+    version: "1.2.0"
+  charcode:
     dependency: transitive
     description:
-      name: collection
+      name: charcode
       url: "https://pub.dartlang.org"
     source: hosted
-    version: "1.14.11"
-  convert:
+    version: "1.3.1"
+  clock:
     dependency: transitive
     description:
-      name: convert
+      name: clock
       url: "https://pub.dartlang.org"
     source: hosted
-    version: "2.1.1"
-  crypto:
+    version: "1.1.0"
+  collection:
     dependency: transitive
     description:
-      name: crypto
+      name: collection
       url: "https://pub.dartlang.org"
     source: hosted
-    version: "2.1.3"
+    version: "1.15.0"
   cupertino_icons:
     dependency: "direct main"
     description:
       name: cupertino_icons
       url: "https://pub.dartlang.org"
     source: hosted
-    version: "0.1.3"
+    version: "1.0.4"
+  fake_async:
+    dependency: transitive
+    description:
+      name: fake_async
+      url: "https://pub.dartlang.org"
+    source: hosted
+    version: "1.2.0"
   flutter:
     dependency: "direct main"
     description: flutter
@@ -74,55 +67,34 @@ packages:
     description: flutter
     source: sdk
     version: "0.0.0"
-  image:
+  matcher:
     dependency: transitive
     description:
-      name: image
+      name: matcher
       url: "https://pub.dartlang.org"
     source: hosted
-    version: "2.1.4"
-  matcher:
+    version: "0.12.11"
+  material_color_utilities:
     dependency: transitive
     description:
-      name: matcher
+      name: material_color_utilities
       url: "https://pub.dartlang.org"
     source: hosted
-    version: "0.12.6"
+    version: "0.1.3"
   meta:
     dependency: transitive
     description:
       name: meta
       url: "https://pub.dartlang.org"
     source: hosted
-    version: "1.1.8"
+    version: "1.7.0"
   path:
     dependency: transitive
     description:
       name: path
       url: "https://pub.dartlang.org"
     source: hosted
-    version: "1.6.4"
-  pedantic:
-    dependency: transitive
-    description:
-      name: pedantic
-      url: "https://pub.dartlang.org"
-    source: hosted
-    version: "1.8.0+1"
-  petitparser:
-    dependency: transitive
-    description:
-      name: petitparser
-      url: "https://pub.dartlang.org"
-    source: hosted
-    version: "2.4.0"
-  quiver:
-    dependency: transitive
-    description:
-      name: quiver
-      url: "https://pub.dartlang.org"
-    source: hosted
-    version: "2.0.5"
+    version: "1.8.0"
   sky_engine:
     dependency: transitive
     description: flutter
@@ -134,62 +106,55 @@ packages:
       name: source_span
       url: "https://pub.dartlang.org"
     source: hosted
-    version: "1.5.5"
+    version: "1.8.1"
   stack_trace:
     dependency: transitive
     description:
       name: stack_trace
       url: "https://pub.dartlang.org"
     source: hosted
-    version: "1.9.3"
+    version: "1.10.0"
   stream_channel:
     dependency: transitive
     description:
       name: stream_channel
       url: "https://pub.dartlang.org"
     source: hosted
-    version: "2.0.0"
+    version: "2.1.0"
   string_scanner:
     dependency: transitive
     description:
       name: string_scanner
       url: "https://pub.dartlang.org"
     source: hosted
-    version: "1.0.5"
+    version: "1.1.0"
   term_glyph:
     dependency: transitive
     description:
       name: term_glyph
       url: "https://pub.dartlang.org"
     source: hosted
-    version: "1.1.0"
+    version: "1.2.0"
   test_api:
     dependency: transitive
     description:
       name: test_api
       url: "https://pub.dartlang.org"
     source: hosted
-    version: "0.2.11"
+    version: "0.4.8"
   typed_data:
     dependency: transitive
     description:
       name: typed_data
       url: "https://pub.dartlang.org"
     source: hosted
-    version: "1.1.6"
+    version: "1.3.0"
   vector_math:
     dependency: transitive
     description:
       name: vector_math
       url: "https://pub.dartlang.org"
     source: hosted
-    version: "2.0.8"
-  xml:
-    dependency: transitive
-    description:
-      name: xml
-      url: "https://pub.dartlang.org"
-    source: hosted
-    version: "3.5.0"
+    version: "2.1.1"
 sdks:
-  dart: ">=2.4.0 <3.0.0"
+  dart: ">=2.16.1 <3.0.0"
diff --git a/pubspec.yaml b/pubspec.yaml
index 86cc28a..1f97336 100644
--- a/pubspec.yaml
+++ b/pubspec.yaml
@@ -14,7 +14,7 @@ description: A new Flutter project.
 version: 1.0.0+1
 
 environment:
-  sdk: ">=2.1.0 <3.0.0"
+  sdk: '>=2.16.1 <3.0.0'
 
 dependencies:
   flutter:
@@ -22,7 +22,7 @@ dependencies:
 
   # The following adds the Cupertino Icons font to your application.
   # Use with the CupertinoIcons class for iOS style icons.
-  cupertino_icons: ^0.1.2
+  cupertino_icons: ^1.0.4
 
 dev_dependencies:
   flutter_test:
diff --git a/web/favicon.png b/web/favicon.png
new file mode 100644
index 0000000..8aaa46a
Binary files /dev/null and b/web/favicon.png differ
diff --git a/web/icons/Icon-192.png b/web/icons/Icon-192.png
new file mode 100644
index 0000000..b749bfe
Binary files /dev/null and b/web/icons/Icon-192.png differ
diff --git a/web/icons/Icon-512.png b/web/icons/Icon-512.png
new file mode 100644
index 0000000..88cfd48
Binary files /dev/null and b/web/icons/Icon-512.png differ
diff --git a/web/icons/Icon-maskable-192.png b/web/icons/Icon-maskable-192.png
new file mode 100644
index 0000000..eb9b4d7
Binary files /dev/null and b/web/icons/Icon-maskable-192.png differ
diff --git a/web/icons/Icon-maskable-512.png b/web/icons/Icon-maskable-512.png
new file mode 100644
index 0000000..d69c566
Binary files /dev/null and b/web/icons/Icon-maskable-512.png differ
diff --git a/web/index.html b/web/index.html
index 9730bb3..8972329 100644
--- a/web/index.html
+++ b/web/index.html
@@ -1,10 +1,104 @@
 <!DOCTYPE html>
 <html>
 <head>
+  <!--
+    If you are serving your web app in a path other than the root, change the
+    href value below to reflect the base path you are serving from.
+
+    The path provided below has to start and end with a slash "/" in order for
+    it to work correctly.
+
+    For more details:
+    * https://developer.mozilla.org/en-US/docs/Web/HTML/Element/base
+
+    This is a placeholder for base href that will be replaced by the value of
+    the `--base-href` argument provided to `flutter build`.
+  -->
+  <base href="$FLUTTER_BASE_HREF">
+
   <meta charset="UTF-8">
+  <meta content="IE=Edge" http-equiv="X-UA-Compatible">
+  <meta name="description" content="A new Flutter project.">
+
+  <!-- iOS meta tags & icons -->
+  <meta name="apple-mobile-web-app-capable" content="yes">
+  <meta name="apple-mobile-web-app-status-bar-style" content="black">
+  <meta name="apple-mobile-web-app-title" content="doctor_booking_app">
+  <link rel="apple-touch-icon" href="icons/Icon-192.png">
+
+  <!-- Favicon -->
+  <link rel="icon" type="image/png" href="favicon.png"/>
+
   <title>doctor_booking_app</title>
+  <link rel="manifest" href="manifest.json">
 </head>
 <body>
-  <script src="main.dart.js" type="application/javascript"></script>
+  <!-- This script installs service_worker.js to provide PWA functionality to
+       application. For more information, see:
+       https://developers.google.com/web/fundamentals/primers/service-workers -->
+  <script>
+    var serviceWorkerVersion = null;
+    var scriptLoaded = false;
+    function loadMainDartJs() {
+      if (scriptLoaded) {
+        return;
+      }
+      scriptLoaded = true;
+      var scriptTag = document.createElement('script');
+      scriptTag.src = 'main.dart.js';
+      scriptTag.type = 'application/javascript';
+      document.body.append(scriptTag);
+    }
+
+    if ('serviceWorker' in navigator) {
+      // Service workers are supported. Use them.
+      window.addEventListener('load', function () {
+        // Wait for registration to finish before dropping the <script> tag.
+        // Otherwise, the browser will load the script multiple times,
+        // potentially different versions.
+        var serviceWorkerUrl = 'flutter_service_worker.js?v=' + serviceWorkerVersion;
+        navigator.serviceWorker.register(serviceWorkerUrl)
+          .then((reg) => {
+            function waitForActivation(serviceWorker) {
+              serviceWorker.addEventListener('statechange', () => {
+                if (serviceWorker.state == 'activated') {
+                  console.log('Installed new service worker.');
+                  loadMainDartJs();
+                }
+              });
+            }
+            if (!reg.active && (reg.installing || reg.waiting)) {
+              // No active web worker and we have installed or are installing
+              // one for the first time. Simply wait for it to activate.
+              waitForActivation(reg.installing || reg.waiting);
+            } else if (!reg.active.scriptURL.endsWith(serviceWorkerVersion)) {
+              // When the app updates the serviceWorkerVersion changes, so we
+              // need to ask the service worker to update.
+              console.log('New service worker available.');
+              reg.update();
+              waitForActivation(reg.installing);
+            } else {
+              // Existing service worker is still good.
+              console.log('Loading app from service worker.');
+              loadMainDartJs();
+            }
+          });
+
+        // If service worker doesn't succeed in a reasonable amount of time,
+        // fallback to plaint <script> tag.
+        setTimeout(() => {
+          if (!scriptLoaded) {
+            console.warn(
+              'Failed to load app from service worker. Falling back to plain <script> tag.',
+            );
+            loadMainDartJs();
+          }
+        }, 4000);
+      });
+    } else {
+      // Service workers not supported. Just drop the <script> tag.
+      loadMainDartJs();
+    }
+  </script>
 </body>
 </html>
diff --git a/web/manifest.json b/web/manifest.json
new file mode 100644
index 0000000..3de8760
--- /dev/null
+++ b/web/manifest.json
@@ -0,0 +1,35 @@
+{
+    "name": "doctor_booking_app",
+    "short_name": "doctor_booking_app",
+    "start_url": ".",
+    "display": "standalone",
+    "background_color": "#0175C2",
+    "theme_color": "#0175C2",
+    "description": "A new Flutter project.",
+    "orientation": "portrait-primary",
+    "prefer_related_applications": false,
+    "icons": [
+        {
+            "src": "icons/Icon-192.png",
+            "sizes": "192x192",
+            "type": "image/png"
+        },
+        {
+            "src": "icons/Icon-512.png",
+            "sizes": "512x512",
+            "type": "image/png"
+        },
+        {
+            "src": "icons/Icon-maskable-192.png",
+            "sizes": "192x192",
+            "type": "image/png",
+            "purpose": "maskable"
+        },
+        {
+            "src": "icons/Icon-maskable-512.png",
+            "sizes": "512x512",
+            "type": "image/png",
+            "purpose": "maskable"
+        }
+    ]
+}