Blog
The iPhone Duo developer blog.
Practical guides to adapting apps and games for the first foldable iPhone, from size classes and the hinge to App Store screenshots.
- Developers
App Intents in iOS 27: Siri, App Schemas and the Semantic Index
How App Intents work with Siri in iOS 27: App Schemas, IndexedEntity and the semantic index, on-screen awareness and IntentValueRepresentation on iPhone Duo.
· 7 min read - App Store
App Store Screenshot Sizes 2026: iPhone Duo and the New Slots
Every App Store screenshot size for 2026: the renamed iPhone slots, the required 1206 × 2622 slot, iPhone Duo outer and inner sizes, and what to show first.
· 8 min read - Developers
ArrangementView in SwiftUI: Split vs Overlay on iPhone Duo
How SwiftUI ArrangementView places a primary and secondary view on iPhone Duo: split vs overlay styles, layout ratios, the hinge, and size classes per pane.
· 8 min read - Developers
iPhone Duo Hinge State: onHingeChange and UIHingeInteraction
Read the iPhone Duo hinge state and angle with onHingeChange or UIHingeInteraction in iOS 27.1, use it for effects and game controls, and see games that do.
· 6 min read - Developers
iPhone Duo Reserved Regions: Keep Your UI Off the Fold
Use iPhone Duo reserved regions in SwiftUI to find the fold and cameras: reservedRegions(kind:), .division vs .occlusion, .includeInactive, and frames.
· 8 min read - Developers
iPhone Duo Safe Area and Content Margins: A Developer Guide
iPhone Duo puts controls at the side, so safe areas and margins are uneven. Handle horizontal insets and adopt .contentMargins(for: .container) in iOS 27.1.
· 7 min read - Developers
iPhone Duo Sheet Presentation: Placement and Corners
How sheet presentation works on iPhone Duo: presentationPlacement for leading, trailing or center sheets, plus concentricCornerRadii for matching corners.
· 8 min read - Developers
iPhone Duo Size Classes: Folded, Half-Open and Open Explained
Which size classes iPhone Duo reports folded, half-open and open, why to adapt to size classes instead of orientation, and SwiftUI and UIKit code to do it.
· 7 min read - Developers
iPhone Duo Vertical Toolbar: How Bars Move to the Edge
How the iPhone Duo vertical toolbar works: when bars go vertical, symbols and titles, visibility priority, pinned actions, opting out, and custom bars.
· 7 min read
Make the fold part of your app.
We showcase apps and games that do something real with iPhone Duo. Send us yours with a link to it on the App Store, or see what other developers have built.