Mobile

## Lifecycle Awareness - App can be killed anytime in background—save state before backgrounding - Restore state on return—user expects to continue where they left off - Handle low memory warnings—release caches, non-essential resources - Background tasks have time limits—complete or request extension ## Permissions - Ask in context, not at launch—explain why when requesting - Degrade gracefully if denied—app should still work with reduced features - Don't ask for unnecessary permissions—users notice and distrust - Re-request after demonstrating value—not immediately after denial ## Offline First - Assume network is unreliable—design for offline, sync when possible - Cache aggressively—previous content better than loading spinner - Queue actions for retry—don't fail on network error - Conflict resolution strategy—last write wins or manual merge - Show sync status—user should know if data is current ## Performance - Target 60fps—dropped frames feel janky - Main thread for UI only—heavy work on background threads - Memory matters more than desktop—constrained devices, aggressive OS killing - Battery awareness—reduce location polling, network requests when possible - Startup time under 2 seconds—first impression matters ## Navigation Patterns - Follow platform conventions—iOS back gesture, Android back button - Navigation stack manageable—don't go 10 levels deep - Deep link to any screen—shareable, notification taps work - Preserve scroll position on return—don't jump to top ## Notifications - Push for time-sensitive external events—new message, delivery update - Local for reminders, timers—user-initiated - Don't spam—users will disable; quality over quantity - Actionable when possible—reply, mark done from notification - Group related notifications—less intrusive ## Deep Linking - Universal Links (iOS) / App Links (Android) for owned domains - Handle gracefully when app not installed—fallback to web - Parse parameters safely—malicious links exist - Test all entry points—not just main launch ## Storage - Secure storage for tokens, credentials—Keychain, Keystore - User data survives reinstall where appropriate—cloud backup - Cache is cache—can be cleared; don't store critical data - Large files: consider on-demand download—not bundled in app ## Input Handling - Keyboard avoidance—content shifts to stay visible - Dismiss keyboard appropriately—tap outside, scroll, submit - Input accessories for relevant actions—next field, done, toolbar - Paste, autofill support—reduce typing on small keyboards ## Touch and Gestures - 44pt minimum touch target—consistent with platform guidelines - System gestures reserved—don't override swipe from edge - Gesture discoverability—hint or teach, don't assume knowledge - Haptic feedback for significant actions—confirmation, errors ## Accessibility - VoiceOver (iOS) / TalkBack (Android) testing—navigate entire app - Dynamic type support—text scales with user preference - Sufficient contrast—check in accessibility inspector - Labels on all interactive elements—not just visible text ## Testing - Real devices essential—simulators miss performance, sensors, edge cases - Multiple OS versions—support at least current minus 2 - Different screen sizes—small phones to tablets - Network conditions—slow, intermittent, offline ## App Store Survival - Read rejection reasons before submitting—common pitfalls documented - Privacy policy required—explain data collection - Login test account for reviewers—if auth required - No placeholder content—everything functional in review build - Update regularly—abandoned apps get deprioritized