iOS 27 redesigns controls and apps for iPhone Duo foldable screens

The Verge reports that Apple completely revamped iOS 27’s controls and apps specifically for the iPhone Duo foldable. Controls that traditionally sat at the bottom or top are now moved to the side to stay within thumb reach when the device is open. Every app’s layout is adjusted to take advantage of the increased interior real estate and the wider aspect ratio of the external screen. Additionally, iOS 27 introduces a standby mode that turns the Duo into a smart display when placed in a tent orientation.

For engineers building or updating apps, the side-aligned controls mean that existing bottom-anchored toolbars may need repositioning to avoid being obscured. The dual-screen layout requires apps to support two simultaneous viewports, with a scrollable Today View on the left and app icons on the right, or to adapt content to the wider external screen when folded. Developers must also handle the new status bar placement, moving Wi-Fi, clock and other icons to the top right corner to maximize vertical space. Finally, integrating Apple Pencil input adds another event stream to manage, though the Verge notes that Pencil support may not be available at launch and will arrive later this year.

Adoption costs include UI redesign work, additional testing across the various foldable orientations (book-like, tent, fully open), and validation of Pencil interactions if the feature is enabled. Apps that do not update may appear with controls misplaced or status bars overlapping content, reducing usability on the Duo. The standby mode, while useful for glanceable information, requires apps to opt-in or adapt to a fullscreen widget view, otherwise they will simply be suspended. Because the Duo is the first iPhone with a flexible screen, older iPhone models will not experience these changes, limiting the scope of the update to the new hardware.

The Verge article emphasizes that Apple did not simply port iOS as is, but considered the implications of the foldable form factor, drawing on iPadOS multitasking experience. This careful approach suggests that the changes are intended to feel natural and intuitive, reducing the learning curve for users. Consequently, engineers can expect the new UI patterns to be stable, but they must still invest effort to align their apps with the revised guidelines.