Android Development Cheat Sheet

A single-page, colour-coded summary of the Android essentials targeting Android 17 (API 37), Android Gradle Plugin 9.4, Kotlin 2.4.20 and Compose BOM 2026.09.00 — project setup and Gradle build variants, the manifest and app components, the classic View-based UI toolkit (Activities, Fragments, RecyclerView, custom views), Jetpack Compose (fundamentals, layouts, state, Material 3, navigation, animation, adaptive layouts, accessibility), the recommended app architecture and the Views-to-Compose migration path, the data and networking libraries (DataStore, Room, Retrofit/OkHttp/Ktor, Coil/Glide, Hilt/Koin), system integration (background work, notifications, permissions, device features, graphics), quality (unit and instrumented testing, debugging and performance), and building, signing, publishing and automating releases — handy for quick memorization or as a printable desk reference.

For the full explanation, every option, and additional examples, see the dedicated pages:

Foundations & tooling — Getting Started with Android, Project Structure, Gradle and Build Variants, App Components, the Manifest and Intents, and Resources, Configuration, Localization and Themes.

Classic View-based UI — Activities and the Activity Lifecycle, Fragments and the Fragment Lifecycle, Views, XML Layouts, View Binding and Material Components, RecyclerView and Lists, Custom Views, Touch, Drawing and View Animation, and Navigation with Fragments (Navigation Component, Drawer, Bottom Nav, Tabs).

Jetpack Compose — Jetpack Compose Fundamentals, Compose Layouts, Modifiers and Lazy Lists, State, Recomposition and Side Effects in Compose, Material 3 and Theming in Compose, Navigation in Compose (Navigation Compose and Navigation 3), Compose Animation and Gestures, Adaptive Layouts, Edge-to-Edge and Large Screens, and Accessibility (Views and Compose).

Architecture: old vs. new — Recommended App Architecture (UI, Domain and Data Layers), ViewModel, Lifecycle-Aware Components, Coroutines and Flow, Saving UI State: Views vs. Compose, Views, Fragments and Activities vs. Compose: Architecture Comparison, and Migrating from Views to Compose.

Data, networking & libraries — Local Storage: DataStore, Files, Scoped Storage and MediaStore, Room Database and Paging, Networking with Retrofit, OkHttp and Ktor, Image Loading, Caching and Transformations with Coil and Glide, and Dependency Injection with Hilt, Dagger and Koin.

System integration & device features — Background Work: WorkManager, Services and Alarms, Notifications, Firebase Cloud Messaging and App Widgets (Glance), Permissions, Privacy and Security, Camera, Location, Sensors, Media and Connectivity, and Graphics: Canvas, OpenGL ES and GLTextureView.

Quality: testing, debugging & performance — Unit Testing with JUnit, Mockito, MockK and Robolectric, Instrumented and UI Testing (Espresso, Compose Testing, UI Automator), and Debugging, Code Quality and Performance.

Build, ship & automate — Building, Signing and Preparing a Release, Publishing on Google Play, Building and Publishing Android Libraries to Maven Central, and CI/CD with GitHub Actions.