Alarmy — Android Alarm App with Memory Pattern Dismiss Challenge

A reliable Android alarm app built with Kotlin, MVVM architecture, and Room Database. Alarms cannot be dismissed by simply tapping a button — users must complete a memory pattern game on a 3x3 grid.

Features

• Multiple alarms with create/edit/delete support
• Repeat days (Mon–Sun toggle), labels, AM/PM and 24-hour format
• Custom ringtone selection and vibration toggle
• Snooze with configurable delay (5/10/15 min or disabled)
• Persistent notification showing next upcoming alarm
• Memory Pattern Dismiss Challenge — 3x3 grid game with Easy/Medium/Hard difficulty
• Dark theme by default
• Survives Doze, battery saver, app kill, and device restart

Setup

1. Open the project in Android Studio Hedgehog (2023.1.1) or later
2. Sync Gradle — dependencies download automatically
3. Connect a device or emulator (min SDK 26 / Android 8.0)
4. Run the app

Permissions Explained

Permission	Why
SCHEDULE_EXACT_ALARM / USE_EXACT_ALARM	Schedule alarms at exact times
USE_FULL_SCREEN_INTENT	Show alarm over lock screen
WAKE_LOCK	Keep CPU awake during alarm
RECEIVE_BOOT_COMPLETED	Re-register alarms after reboot
DISABLE_KEYGUARD	Dismiss lock screen for alarm display
REQUEST_IGNORE_BATTERY_OPTIMIZATIONS	Prevent system from killing alarm scheduling
FOREGROUND_SERVICE + FOREGROUND_SERVICE_MEDIA_PLAYBACK	Keep alarm sound playing reliably
POST_NOTIFICATIONS	Show alarm and next-alarm notifications (Android 13+)
VIBRATE	Vibrate on alarm
Device Admin	Prevents force-stop of the app

On first launch, the app prompts for all critical permissions. A warning banner appears on the home screen if any are missing.

Architecture

com.alarmapp.alarmy/
├── AlarmyApp.kt                  # Application class (notification channels)
├── data/
│   ├── Alarm.kt                  # Room Entity
│   ├── AlarmDao.kt               # Data Access Object
│   ├── AlarmDatabase.kt          # Room Database singleton
│   ├── AlarmRepository.kt        # Repository pattern
│   └── AlarmViewModel.kt         # MVVM ViewModel
├── game/
│   └── MemoryGameView.kt         # Custom View — 3x3 memory pattern game
├── receiver/
│   ├── AlarmReceiver.kt          # BroadcastReceiver — triggers alarm
│   ├── BootReceiver.kt           # Reschedules alarms after reboot
│   └── AlarmDeviceAdminReceiver.kt
├── service/
│   └── AlarmService.kt           # Foreground service — plays sound/vibration
├── ui/
│   ├── MainActivity.kt           # Alarm list + permission management
│   ├── AddEditAlarmActivity.kt   # Create/edit alarm screen
│   ├── AlarmActivity.kt          # Full-screen alarm + memory game
│   └── AlarmAdapter.kt           # RecyclerView adapter
└── util/
    ├── AlarmScheduler.kt         # AlarmManager scheduling logic
    └── PermissionHelper.kt       # Permission checking utilities

How Alarm Reliability Works

1. setAlarmClock() — highest priority AlarmManager API; survives Doze mode
2. Foreground Service — plays sound via STREAM_ALARM at max volume, keeps playback alive
3. Boot Receiver — re-registers all enabled alarms on device restart
4. Battery optimization exemption — prevents system from limiting the app
5. Device Admin — prevents user from force-stopping the app
6. Window flags — FLAG_SHOW_WHEN_LOCKED, FLAG_TURN_SCREEN_ON, etc. ensure the alarm shows over lock screen

Testing on Emulator vs Real Device

Emulator

• Exact alarms work but Doze testing requires adb commands:

  adb shell dumpsys deviceidle force-idle
  adb shell dumpsys deviceidle unforce
  

• Ringtone picker may show limited options
• Device Admin works but has no real effect on emulator

Real Device

• Grant all permissions on first launch for best results
• Test with screen off, app killed, and after reboot
• Some OEMs (Xiaomi, Huawei, Samsung) have extra battery restrictions — the battery optimization exemption dialog handles most cases
• To test alarm sounds at full volume, ensure the alarm stream isn't muted

Memory Pattern Game

The dismiss challenge shows a 3x3 grid. Blocks highlight one by one in a random sequence. The user must tap them in the exact same order.

• Easy: 3 blocks in sequence
• Medium: 5 blocks in sequence
• Hard: 7 blocks in sequence

Wrong taps trigger a shake animation, reset the sequence with a new random pattern, and increment the attempt counter. The alarm keeps ringing until the pattern is completed correctly.

Build

./gradlew assembleDebug

APK output: app/build/outputs/apk/debug/app-debug.apk