Official docs outline
4 sections- Essentials
Covers Developing a WidgetKit strategy, ActivityKit updates.
- Starting a Live Activity
Covers Displaying live data with Live Activities, Starting and updating Live Activities with ActivityKit push notifications, Activity, Emoji Rangers: Supporting Live Activities, interactivity, and animations.
- User interface
Covers Creating custom views for Live Activities, Adding accessible descriptions to widgets and Live Activities, Launching your app from a Live Activity.
- Widget ecosystem
Covers Creating a widget extension, Animating data updates in widgets and Live Activities, Creating views for widgets, Live Activities, and watch complications, Linking to specific app scenes from your widget or Live Activity.
Each section links to the official page. Titles and summaries by Extra Credit; the docs belong to their authors.
More in Apple frameworks
All 394- Accessory Notifications App Frameworks
- Accessory Transport Extension System
- AccessorySetupKit System
- Account & Organizational Data Sharing System
- Account Data Transfer App Frameworks
- Accounts App Services
- AdAttributionKit App Services
- Address Book App Services
- Address Book UI App Services
- AdServices App Services
- AdSupport App Services
- Advanced Commerce API App Services