iPhone Duo Developer Resources · Unofficial developer resource
Build for iPhone Duo
SwiftUI guides, adaptive layouts, fold handling, multiple displays, Xcode tools, and official Apple resources — all in one place.
Updated for iOS 27.1|Xcode 27.1 beta
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Prepare Your App
Make your existing iPhone app work correctly on Duo.
SwiftUI
Adaptive layouts, size classes, safe areas and ReservedRegion.
Fold & Pose
Build layouts that adapt as the device opens and folds.
Multiple Displays
Build experiences across inner and outer displays.
Is your app ready for iPhone Duo?
Apple's adaptation guidance centers on size classes, window scenes, safe areas, Split View, and avoiding hardcoded assumptions about the display.
- Uses adaptive layouts
- Supports dynamic window resizing
- Avoids UIScreen.main
- Handles asymmetric safe areas
- Works in Split View
- Supports different size classes
- Tests every Duo pose
- Avoids content behind the fold
Latest
- Xcode 27.1 beta available
- iPhone Duo design resources available
- New SwiftUI ReservedRegion API
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