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name: mobile-app-debugging description: Mobile app debugging for iOS, Android, cross-platform frameworks. Use for crashes, memory leaks, performance issues, network problems, or encountering Xcode instruments, Android Profiler, React Native debugger, native bridge errors.

Mobile App Debugging

Debug mobile applications across iOS, Android, and cross-platform frameworks.

iOS Debugging (Xcode)

// Breakpoint with condition
// Right-click breakpoint > Edit > Condition: userId == "123"

// LLDB commands
po variable          // Print object
p expression         // Evaluate expression
bt                   // Backtrace

Memory Debugging

• Use Memory Graph Debugger to find retain cycles
• Enable Zombie Objects for use-after-free bugs
• Profile with Instruments > Leaks

Android Debugging (Android Studio)

// Logcat filtering
Log.d("TAG", "Debug message")
Log.e("TAG", "Error", exception)

// Filter: tag:MyApp level:error

Common Issues

• ANR: Check main thread blocking
• OOM: Profile with Memory Profiler
• Layout issues: Use Layout Inspector

React Native

// Remote debugging
// Shake device > Debug JS Remotely

// Console logging
console.log('Debug:', variable);
console.warn('Warning');
console.error('Error');

// Performance Monitor
// Shake > Show Perf Monitor
// Target: 60 FPS, <16ms per frame

Network Debugging

// Intercept requests
XMLHttpRequest.prototype._send = XMLHttpRequest.prototype.send;
XMLHttpRequest.prototype.send = function() {
  console.log('Request:', this._url);
  this._send.apply(this, arguments);
};

Debug Checklist

• Test on physical devices (not just simulators)
• Test on older device models
• Simulate slow 3G network
• Test offline mode
• Check memory under load
• Test rotation and safe areas
• Verify 60 FPS target

Performance Targets

Metric	Target
Frame rate	60 FPS (16ms/frame)
Memory	<100MB
App launch	<2 seconds