UIKit App Modernization Skill

Purpose

Modernize UIKit apps to behave correctly on modern iOS by:

• Eliminating references to legacy shared-state APIs
• Migrating from application lifecycle to scene lifecycle
• Supporting dynamic scene sizing and multi-window environments

Scope

This skill performs specific, targeted modernizations in both Swift and Objective-C codebases:

• Replace legacy shared-state APIs with context-appropriate modern APIs
• Migrate to scene-based lifecycle
• Update apps to support a resizable user interface by removing usage of:
  • main screen (UIScreen.mainScreen, UIScreen.main)
  • interface orientation (interfaceOrientation)
  • assumptions of symmetric safe areas (safeAreaLayoutGuide, safeAreaInsets)

Core Principles