Apple has opened App Store Connect submissions for apps and games optimized for iPhone Duo, putting foldable-ready software in the review pipeline ahead of the device’s October 23 commercial debut. The company is also setting a future requirement: from April 2027, submitted apps and games must include screenshots for iPhone Duo.
Developers are being asked to build or recompile apps with Xcode 27.1, which adds iPhone Duo support. Its Device Hub tool can be used to check interfaces across different orientations and device positions, an important step for software that must react when the phone is unfolded while an app is already running.
Apple’s guidance makes clear that recompiling alone will not make every app fully suited to the larger inner display. Developers need to remove fixed dimensions and test resizing behavior so buttons and content do not become clipped or shift into unsuitable positions during the transition between folded and unfolded states.
- Apps built with the iOS 26 SDK or earlier can run on iPhone Duo, but remain centered on the inner display with unused surrounding space.
- Apps using the iOS 27 SDK can expand across most of the inner display.
- Apps using iOS 27.1 or later can use the full display area, with navigation and toolbars adapted to the new form factor.
The distinction will matter for older software that may otherwise appear as a phone-sized window or leave black bars and unused display space on the foldable’s inner screen. Apple is also running workshops focused on adapting apps for iPhone Duo before the device reaches buyers.
The April 2027 deadline applies to submitted apps and games rather than only newly created titles, making dedicated iPhone Duo presentation assets the next confirmed compliance milestone for App Store developers.
