Native Android applications built with Kotlin and Jetpack Compose, designed to be reliable on real devices and maintainable as the product grows.
Every screen in an Android app I build follows MVVM with Hilt dependency injection. ViewModels own the state, repositories own the data, and the UI renders what it's told. This separation means I can swap a Room DAO for an API call without touching a single Composable. Clean boundaries are not over-engineering. They are the minimum viable structure for code that lasts.
In Itqan, the Quran memorization app, the core is a from-scratch implementation of the SuperMemo-2 algorithm. Every review interval is calculated from an Easiness Factor that updates after each quiz response, with edge case guards: EF clamped to a safe floor, interval minimum set to one day to prevent infinite-loop review states. The forgetting curve is modeled via Ebbinghaus decay. Mastery scores drop proportionally over time when the user is inactive, not because of a hard-coded timer.
All persistent state lives in Room with typed entities and typed DAOs. UI state lives in StateFlow exposed from ViewModels. Nothing is shared between layers without going through the repository contract. Coroutines handle all async work with no callbacks, no threading bugs, and no leaked contexts. WorkManager schedules background tasks that survive process death.
AudioPlaybackService runs as a foreground service with a MediaSession that controls playback from the lock screen and notification shade, the same way Spotify does it. Security and tamper detection run at startup without blocking the main thread. Google Drive backup serializes the entire Room database and restores it across reinstalls. These are not demos. They run in production on real hardware.
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