watchOS

1# watchOS Development
2 
3Comprehensive guidance for watchOS app development with SwiftUI, Watch Connectivity, and complications.
4 
5## When This Skill Activates
6 
7Use this skill when the user:
8- Is building a watchOS app or Watch extension
9- Asks about Watch Connectivity (iPhone ↔ Watch sync)
10- Needs help with complications or ClockKit
11- Wants to implement watch-specific UI patterns
12- Asks about **WidgetKit complications** or migrating from ClockKit to WidgetKit
13- Wants to build **watch face complications** (accessoryCircular, accessoryRectangular, accessoryCorner, accessoryInline)
14- Asks about **HealthKit on watchOS**, workout sessions, heart rate, or fitness tracking
15- Needs **Extended Runtime sessions** for background workout tracking
16- Wants to build **watchOS widgets** or Smart Stack widgets
17- Asks about **widget relevance**, Smart Stack ordering, or widget suggestions
18- Needs to share widgets **cross-platform** between iOS and watchOS
19- Asks about **watchOS accessibility** — VoiceOver, AssistiveTouch, or Dynamic Type on the Watch
20 
21## Key Principles
22 
23### 1. Watch-First Design
24- Glanceable content - users look for seconds, not minutes
25- Quick interactions - 2 seconds or less
26- Essential information only - no scrolling walls of text
27- Large touch targets - minimum 38pt height
28 
29### 2. Independent vs Companion
30- Prefer independent Watch apps when possible
31- Use Watch Connectivity for data sync, not as dependency
32- Cache data locally for offline access
33…