diff --git a/app/build.gradle b/app/build.gradle
index ff94355..7dc8893 100644
--- a/app/build.gradle
+++ b/app/build.gradle
@@ -32,6 +32,19 @@ android {
             proguardFiles getDefaultProguardFile('proguard-android-optimize.txt'), 'proguard-rules.pro'
         }
     }
+    flavorDimensions += "version"
+    productFlavors {
+        freeVersion {
+            dimension "version"
+            applicationId "com.phpbg.easysync.trial"
+            resValue "string", "flavored_app_name", "Easy Sync Trial"
+
+        }
+        paidVersion {
+            dimension "version"
+            resValue "string", "flavored_app_name", "Easy Sync"
+        }
+    }
     compileOptions {
         sourceCompatibility JavaVersion.VERSION_1_8
         targetCompatibility JavaVersion.VERSION_1_8
diff --git a/app/src/main/AndroidManifest.xml b/app/src/main/AndroidManifest.xml
index 09994a5..85464bc 100644
--- a/app/src/main/AndroidManifest.xml
+++ b/app/src/main/AndroidManifest.xml
@@ -20,7 +20,7 @@
         android:dataExtractionRules="@xml/data_extraction_rules"
         android:fullBackupContent="@xml/backup_rules"
         android:icon="@mipmap/ic_launcher"
-        android:label="@string/app_name"
+        android:label="@string/flavored_app_name"
         android:localeConfig="@xml/locales_config"
         android:networkSecurityConfig="@xml/network_security_config"
         android:roundIcon="@mipmap/ic_launcher_round"
diff --git a/app/src/main/java/com/phpbg/easysync/MyApp.kt b/app/src/main/java/com/phpbg/easysync/MyApp.kt
index 620df74..9206df9 100644
--- a/app/src/main/java/com/phpbg/easysync/MyApp.kt
+++ b/app/src/main/java/com/phpbg/easysync/MyApp.kt
@@ -25,11 +25,36 @@
 package com.phpbg.easysync
 
 import android.app.Application
+import android.content.Context
 import android.os.StrictMode
+import java.lang.System.currentTimeMillis
+import kotlin.math.floor
+import kotlin.math.max
+
+const val TRIAL_DURATION_DAYS = 30
 
 class MyApp : Application() {
     init {
         if (BuildConfig.DEBUG)
             StrictMode.enableDefaults()
     }
+
+    companion object {
+        fun isTrial(): Boolean {
+            @Suppress("KotlinConstantConditions")
+            return (BuildConfig.FLAVOR == "freeVersion")
+        }
+
+        fun getTrialRemainingDays(context: Context): Int {
+            val installed = context
+                .packageManager
+                .getPackageInfo(context.packageName, 0).firstInstallTime
+            val now = currentTimeMillis()
+            return max(0, TRIAL_DURATION_DAYS- floor((now-installed)/(24*3600*1000).toFloat()).toInt())
+        }
+
+        fun isTrialExpired(context: Context): Boolean {
+            return isTrial() && getTrialRemainingDays(context) == 0
+        }
+    }
 }
\ No newline at end of file
diff --git a/app/src/main/java/com/phpbg/easysync/Notifications.kt b/app/src/main/java/com/phpbg/easysync/Notifications.kt
index d786429..ddc263e 100644
--- a/app/src/main/java/com/phpbg/easysync/Notifications.kt
+++ b/app/src/main/java/com/phpbg/easysync/Notifications.kt
@@ -25,5 +25,6 @@
 package com.phpbg.easysync
 
 enum class Notifications(val id: Int) {
-    MISSING_PERMISSIONS(1)
+    MISSING_PERMISSIONS(1),
+    TRIAL_EXPIRED(2)
 }
\ No newline at end of file
diff --git a/app/src/main/java/com/phpbg/easysync/ui/MainActivity.kt b/app/src/main/java/com/phpbg/easysync/ui/MainActivity.kt
index 51f92cc..e92ff0b 100644
--- a/app/src/main/java/com/phpbg/easysync/ui/MainActivity.kt
+++ b/app/src/main/java/com/phpbg/easysync/ui/MainActivity.kt
@@ -24,6 +24,7 @@
 
 package com.phpbg.easysync.ui
 
+import android.content.ActivityNotFoundException
 import android.content.Intent
 import android.content.res.Configuration
 import android.net.Uri
@@ -47,6 +48,7 @@ import androidx.compose.material.icons.Icons
 import androidx.compose.material.icons.filled.Cancel
 import androidx.compose.material.icons.filled.CheckCircle
 import androidx.compose.material.icons.filled.Help
+import androidx.compose.material.icons.filled.Info
 import androidx.compose.material.icons.filled.Schedule
 import androidx.compose.material.icons.filled.Settings
 import androidx.compose.material.icons.filled.Warning
@@ -58,8 +60,10 @@ import androidx.compose.material3.SnackbarHostState
 import androidx.compose.material3.Surface
 import androidx.compose.material3.Text
 import androidx.compose.runtime.Composable
+import androidx.compose.runtime.IntState
 import androidx.compose.runtime.State
 import androidx.compose.runtime.livedata.observeAsState
+import androidx.compose.runtime.mutableIntStateOf
 import androidx.compose.runtime.mutableStateOf
 import androidx.compose.runtime.remember
 import androidx.compose.runtime.rememberCoroutineScope
@@ -67,6 +71,7 @@ import androidx.compose.ui.Alignment
 import androidx.compose.ui.Modifier
 import androidx.compose.ui.graphics.Color
 import androidx.compose.ui.platform.LocalContext
+import androidx.compose.ui.res.pluralStringResource
 import androidx.compose.ui.res.stringResource
 import androidx.compose.ui.tooling.preview.Preview
 import androidx.compose.ui.unit.dp
@@ -126,7 +131,9 @@ class MainActivity : ComponentActivity() {
                         showDavStatus = viewModel.showDavStatus,
                         isDavLoading = viewModel.isDavLoading,
                         isDavConnected = viewModel.isDavConnected,
-                        hasOptionalPermissions = hasOptionalPermissions
+                        isTrial = viewModel.isTrial,
+                        hasOptionalPermissions = hasOptionalPermissions,
+                        trialRemainingDays = viewModel.trialRemainingDays
                     )
                 }
             }
@@ -148,7 +155,9 @@ private fun Main(
     showDavStatus: State<Boolean>,
     isDavLoading: State<Boolean>,
     isDavConnected: State<Boolean>,
+    isTrial: State<Boolean>,
     hasOptionalPermissions: State<Boolean>,
+    trialRemainingDays: IntState,
 ) {
     val mContext = LocalContext.current
     val syncEnabled = workerState == null || workerState != WorkInfo.State.RUNNING
@@ -163,7 +172,7 @@ private fun Main(
             .padding(16.dp)
             .verticalScroll(rememberScrollState())
     ) {
-        Title(text = stringResource(R.string.app_name))
+        Title(text = stringResource(R.string.flavored_app_name))
 
         val davSettingsHandler = fun(_: Int) {
             val myIntent = Intent(mContext, DavSettingsActivity::class.java)
@@ -247,6 +256,23 @@ private fun Main(
             },
         )
 
+        if (isTrial.value) {
+            val msg = if (trialRemainingDays.intValue == 0) stringResource(R.string.home_trial_over) else pluralStringResource(R.plurals.home_trial_days_left, trialRemainingDays.intValue, trialRemainingDays.intValue)
+            StatusTitleClickable(
+                title = null,
+                actionTitle = msg,
+                statusColor = Color.Gray,
+                statusIcon = Icons.Default.Info,
+                clickHandler = {
+                    try {
+                        mContext.startActivity(Intent(Intent.ACTION_VIEW, Uri.parse("market://details?id=com.phpbg.easysync")))
+                    } catch (e: ActivityNotFoundException) {
+                        mContext.startActivity(Intent(Intent.ACTION_VIEW, Uri.parse("https://play.google.com/store/apps/details?id=com.phpbg.easysync")))
+                    }
+                },
+            )
+        }
+
         Spacer(modifier = Modifier.height(16.dp))
 
         val syncedPercent = if (localCount > 0 && syncedCount >= 0) {
@@ -354,7 +380,29 @@ private fun MainPreview() {
             showDavStatus = remember { mutableStateOf(true) },
             isDavLoading = remember { mutableStateOf(false) },
             isDavConnected = remember { mutableStateOf(true) },
+            isTrial = remember { mutableStateOf(false) },
+            hasOptionalPermissions = remember { mutableStateOf(false) },
+            trialRemainingDays = remember { mutableIntStateOf(0) }
+        )
+    }
+}
+
+@Preview(name = "Trial Mode", showBackground = false)
+@Composable
+private fun MainPreviewTrial() {
+    MyApplicationTheme {
+        Main(
+            fullSyncNowHandler = {},
+            workerState = WorkInfo.State.RUNNING,
+            syncedCount = 10000,
+            localCount = 100,
+            jobCount = -1,
+            showDavStatus = remember { mutableStateOf(true) },
+            isDavLoading = remember { mutableStateOf(false) },
+            isDavConnected = remember { mutableStateOf(true) },
+            isTrial = remember { mutableStateOf(true) },
             hasOptionalPermissions = remember { mutableStateOf(false) },
+            trialRemainingDays = remember { mutableIntStateOf(28) }
         )
     }
 }
\ No newline at end of file
diff --git a/app/src/main/java/com/phpbg/easysync/ui/MainViewModel.kt b/app/src/main/java/com/phpbg/easysync/ui/MainViewModel.kt
index f8e324c..d334138 100644
--- a/app/src/main/java/com/phpbg/easysync/ui/MainViewModel.kt
+++ b/app/src/main/java/com/phpbg/easysync/ui/MainViewModel.kt
@@ -32,6 +32,7 @@ import android.os.Handler
 import android.os.Looper
 import android.provider.MediaStore
 import android.util.Log
+import androidx.compose.runtime.mutableIntStateOf
 import androidx.compose.runtime.mutableStateOf
 import androidx.lifecycle.AndroidViewModel
 import androidx.lifecycle.LiveData
@@ -39,6 +40,7 @@ import androidx.lifecycle.MutableLiveData
 import androidx.lifecycle.map
 import androidx.lifecycle.viewModelScope
 import androidx.work.WorkInfo
+import com.phpbg.easysync.MyApp
 import com.phpbg.easysync.dav.CollectionPath
 import com.phpbg.easysync.dav.MisconfigurationException
 import com.phpbg.easysync.dav.WebDavService
@@ -85,6 +87,9 @@ class MainViewModel(application: Application) : AndroidViewModel(application) {
     val isDavConnected = mutableStateOf(false)
     val isDavLoading = mutableStateOf(false)
 
+    val isTrial = mutableStateOf(false)
+    val trialRemainingDays = mutableIntStateOf(0)
+
     val workInfosList = FullSyncWorker.getLiveData(this.getApplication()).map { x ->
         if (x.isEmpty()) {
             return@map null
@@ -120,6 +125,9 @@ class MainViewModel(application: Application) : AndroidViewModel(application) {
         viewModelScope.launch {
             loadDav()
         }
+
+        isTrial.value = MyApp.isTrial()
+        trialRemainingDays.intValue = MyApp.getTrialRemainingDays(getApplication())
     }
 
     private fun loadImages() {
diff --git a/app/src/main/java/com/phpbg/easysync/worker/FileDetectWorker.kt b/app/src/main/java/com/phpbg/easysync/worker/FileDetectWorker.kt
index 5757691..488c940 100644
--- a/app/src/main/java/com/phpbg/easysync/worker/FileDetectWorker.kt
+++ b/app/src/main/java/com/phpbg/easysync/worker/FileDetectWorker.kt
@@ -32,6 +32,7 @@ import androidx.work.ExistingWorkPolicy
 import androidx.work.OneTimeWorkRequestBuilder
 import androidx.work.WorkManager
 import androidx.work.WorkerParameters
+import com.phpbg.easysync.MyApp
 import com.phpbg.easysync.mediastore.MediaStoreService
 import com.phpbg.easysync.mediastore.URIS
 
@@ -45,6 +46,9 @@ private const val TAG = "FileDetectWorker"
 class FileDetectWorker(appContext: Context, workerParams: WorkerParameters) :
     CoroutineWorker(appContext, workerParams) {
     override suspend fun doWork(): Result {
+        if (MyApp.isTrialExpired(this.applicationContext)) {
+            return Result.success()
+        }
         try {
             _doWork()
         } catch (e: Exception) {
diff --git a/app/src/main/java/com/phpbg/easysync/worker/FullSyncWorker.kt b/app/src/main/java/com/phpbg/easysync/worker/FullSyncWorker.kt
index 7a6d922..6a0885c 100644
--- a/app/src/main/java/com/phpbg/easysync/worker/FullSyncWorker.kt
+++ b/app/src/main/java/com/phpbg/easysync/worker/FullSyncWorker.kt
@@ -39,6 +39,7 @@ import androidx.work.PeriodicWorkRequestBuilder
 import androidx.work.WorkInfo
 import androidx.work.WorkManager
 import androidx.work.WorkerParameters
+import com.phpbg.easysync.MyApp.Companion.isTrialExpired
 import com.phpbg.easysync.Notifications
 import com.phpbg.easysync.R
 import com.phpbg.easysync.dav.MisconfigurationException
@@ -57,6 +58,10 @@ class FullSyncWorker(context: Context, parameters: WorkerParameters) :
                 NotificationManager
 
     override suspend fun doWork(): Result {
+        if (isTrialExpired(this.applicationContext)) {
+            showTrialExpiredNotification()
+            return Result.success()
+        }
         val immediate = inputData.getBoolean(IMMEDIATE_KEY, false)
         return try {
             val syncService = SyncService.getInstance(this.applicationContext)
@@ -83,17 +88,28 @@ class FullSyncWorker(context: Context, parameters: WorkerParameters) :
         }
     }
 
+    private fun showTrialExpiredNotification() {
+        val title = applicationContext.getString(R.string.notification_trial_over_title)
+        val text = applicationContext.getString(R.string.notification_trial_over_text)
+        val notificationId = Notifications.TRIAL_EXPIRED
+        showNotification(title, text, notificationId)
+    }
+
     private fun showMissingPermissionsNotification() {
-        val id = applicationContext.getString(R.string.notification_channel_id)
         val title = applicationContext.getString(R.string.notification_missing_permissions_title)
         val text = applicationContext.getString(R.string.notification_missing_permissions_text)
+        val notificationId = Notifications.MISSING_PERMISSIONS
+        showNotification(title, text, notificationId)
+    }
+
+    private fun showNotification(title: String, text: String, notificationId: Notifications) {
+        val id = applicationContext.getString(R.string.notification_channel_id)
 
         val intent = Intent(this.applicationContext, MainActivity::class.java).apply {
             flags = Intent.FLAG_ACTIVITY_NEW_TASK or Intent.FLAG_ACTIVITY_CLEAR_TASK
         }
         val pendingIntent = PendingIntent.getActivity(this.applicationContext, 0, intent, PendingIntent.FLAG_IMMUTABLE)
 
-
         createChannel(id)
         val notification = Notification.Builder(applicationContext, id)
             .setContentTitle(title)
@@ -105,7 +121,7 @@ class FullSyncWorker(context: Context, parameters: WorkerParameters) :
             .setContentIntent(pendingIntent)
             .build()
 
-        notificationManager.notify(Notifications.MISSING_PERMISSIONS.id, notification)
+        notificationManager.notify(notificationId.id, notification)
     }
 
     private fun createChannel(channelId: String) {
diff --git a/app/src/main/res/values-de/strings.xml b/app/src/main/res/values-de/strings.xml
index d8f7fab..f1b666a 100644
--- a/app/src/main/res/values-de/strings.xml
+++ b/app/src/main/res/values-de/strings.xml
@@ -2,6 +2,8 @@
 <resources>
     <string name="notification_missing_permissions_text">Bitte erteilen Sie Berechtigungen, um die Synchronisation zu ermöglichen</string>
     <string name="notification_missing_permissions_title">Synchronisation fehlgeschlagen</string>
+    <string name="notification_trial_over_title">Synchronisation gestoppt</string>
+    <string name="notification_trial_over_text">Bitte kaufen Sie die Vollversion</string>
     <string name="dav_settings_activity_title">Einstellungen</string>
     <string name="dav_settings_hide_password">Passwort ausblenden</string>
     <string name="dav_settings_password">Passwort</string>
@@ -25,6 +27,11 @@
     <string name="home_permissions_action_fix">Beheben…</string>
     <string name="home_sync_running">läuft</string>
     <string name="home_sync_syncing">synchronisiert</string>
+    <string name="home_trial_over">Die Testversion ist abgelaufen, bitte kaufen Sie die Vollversion</string>
+    <plurals name="home_trial_days_left">
+        <item quantity="one">Testversion: %d Tag verbleibend</item>
+        <item quantity="other">Testversion: %d Tage verbleibend</item>
+    </plurals>
     <string name="permissions_activity_title">Berechtigungen</string>
     <string name="permissions_files_text">Um Ihre Dateien zu synchronisieren, benötigen wir vollen Zugriff auf Ihre Dateien. Gehen Sie zu den Einstellungen, um die Berechtigung zu aktivieren</string>
     <string name="permissions_files_button">Dateieinstellungen</string>
diff --git a/app/src/main/res/values-fr/strings.xml b/app/src/main/res/values-fr/strings.xml
index 5c6e44c..c5c92f6 100644
--- a/app/src/main/res/values-fr/strings.xml
+++ b/app/src/main/res/values-fr/strings.xml
@@ -2,6 +2,8 @@
 <resources>
     <string name="notification_missing_permissions_text">Veuillez accorder les permissions pour permettre la synchronisation</string>
     <string name="notification_missing_permissions_title">Synchronisation KO</string>
+    <string name="notification_trial_over_title">Synchronisation interrompue</string>
+    <string name="notification_trial_over_text">Veuillez acheter la version complète</string>
     <string name="dav_settings_activity_title">Paramètres</string>
     <string name="dav_settings_username">Nom d\'utilisateur</string>
     <string name="dav_settings_password">Mot de passe</string>
@@ -23,6 +25,11 @@
     <string name="home_permissions_action_fix">Corriger…</string>
     <string name="home_sync_running">attente</string>
     <string name="home_sync_syncing">en cours</string>
+    <string name="home_trial_over">La période d\'essai est terminée, veuillez acheter la version complète</string>
+    <plurals name="home_trial_days_left">
+        <item quantity="one">Essai gratuit : %d jour restant</item>
+        <item quantity="other">Essai gratuit : %d jours restants</item>
+    </plurals>
     <string name="dav_settings_title">Paramètres DAV</string>
     <string name="dav_settings_url_insecure">Cette URL n\'est pas sécurisée. Vos données pourront être interceptées. Vous devriez utiliser HTTPS.</string>
     <string name="permissions_activity_title">Permissions</string>
diff --git a/app/src/main/res/values-ru/strings.xml b/app/src/main/res/values-ru/strings.xml
index 3246b88..678f58c 100644
--- a/app/src/main/res/values-ru/strings.xml
+++ b/app/src/main/res/values-ru/strings.xml
@@ -1,6 +1,8 @@
 <resources>
     <string name="notification_missing_permissions_text">Пожалуйста предоставьте разрешения для синхронизации.</string>
     <string name="notification_missing_permissions_title">Синхронизация неуспешна</string>
+    <string name="notification_trial_over_title">Синхронизация остановлена</string>
+    <string name="notification_trial_over_text">Пожалуйста, купите полную версию, чтобы разрешить синхронизацию</string>
     <string name="dav_settings_activity_title">Настройки</string>
     <string name="dav_settings_hide_password">Скрыть пароль</string>
     <string name="dav_settings_password">Пароль</string>
@@ -24,6 +26,13 @@
     <string name="home_permissions_action_fix">Исправить…</string>
     <string name="home_sync_running">выполняется</string>
     <string name="home_sync_syncing">синхронизация</string>
+    <string name="home_trial_over">Испытательный период завершен, пожалуйста, купите полную версию</string>
+    <plurals name="home_trial_days_left">
+        <item quantity="one">Испытание: %d день остался</item>
+        <item quantity="few">Испытание: %d дня осталось</item>
+        <item quantity="many">Испытание: %d дней осталось</item>
+        <item quantity="other">Испытание: %d дней осталось</item>
+    </plurals>
     <string name="permissions_activity_title">Разрешения</string>
     <string name="permissions_files_text">Для синхронизации ваших файлов нам необходим полный доступ к вашим файлам. Зайдите в настройки, чтобы включить разрешение</string>
     <string name="permissions_files_button">Настройки файлов</string>
diff --git a/app/src/main/res/values/strings.xml b/app/src/main/res/values/strings.xml
index 79ad368..c12c2b5 100644
--- a/app/src/main/res/values/strings.xml
+++ b/app/src/main/res/values/strings.xml
@@ -1,8 +1,9 @@
 <resources>
-    <string name="app_name" translatable="false">Easy Sync</string>
     <string name="notification_channel_id" translatable="false">1001</string>
     <string name="notification_missing_permissions_text">Please grant permissions to allow synchronization</string>
     <string name="notification_missing_permissions_title">Synchronization failed</string>
+    <string name="notification_trial_over_title">Synchronization stopped</string>
+    <string name="notification_trial_over_text">Please buy the full version to allow synchronization</string>
     <string name="dav_settings_activity_title">Settings</string>
     <string name="dav_settings_hide_password">Hide password</string>
     <string name="dav_settings_password">Password</string>
@@ -26,6 +27,11 @@
     <string name="home_permissions_action_fix">Fix…</string>
     <string name="home_sync_running">running</string>
     <string name="home_sync_syncing">syncing</string>
+    <string name="home_trial_over">Trial is over, please buy the full version</string>
+    <plurals name="home_trial_days_left">
+        <item quantity="one">Trial: %d day remaining</item>
+        <item quantity="other">Trial: %d days remaining</item>
+    </plurals>
     <string name="permissions_activity_title">Permissions</string>
     <string name="permissions_files_text">In order to synchronize your files we need full access to your files. Go to settings to enable the permission</string>
     <string name="permissions_files_button">File settings</string>