Apple Details How Apps Should Work on iPhone Duo

Apple has published new design guidance for iPhone Duo, detailing how apps should adapt as users open, close, and partially fold its first foldable iPhone.



The device, introduced yesterday, pairs a 5.4-inch outer display with a 7.6-inch inner screen. The guidance shows how that extra space can change an app without requiring users to relearn it.


Mail provides a straightforward example. When the phone is closed, it shows either the inbox or an individual email. Opening it reveals both side by side. Apps should preserve what users are doing as they switch between screens, with the same features accessible in either view.

One noticeable change is the placement of controls. Buttons and navigation bars move to the side on the outer screen, leaving more vertical room for content. They stay there when the phone opens in landscape, while the inner display in portrait retains the familiar horizontal bars.



That arrangement also carries over to multitasking. With two apps open side by side, each places its controls along the outer edge. Split View supports two windows from the same app, such as Safari, and lets users save app pairs to return to later.



Partially folding the phone introduces another adjustment. Alerts and menus move away from the bend, while apps such as Notes adjust their columns to keep content visible. The guidance favors small shifts over dramatic rearrangements.


The hidden inner camera affects the layout, too. When it activates, the interface moves aside to make room for it. Otherwise, the camera stays out of sight. Developers can find the full recommendations in Designing for iPhone Duo.

Several third-party apps are already adapting to the hardware. Netflix lets users browse Clips on the outer display and unfold the phone for a larger viewing experience, while Zoom can show shared content alongside call participants. Slack also uses the expanded screen to display more of a workspace.

iPhone Duo starts at $1,999 in the United States and ships with iOS 27.1. Pre-orders begin October 16, with availability starting October 23. You can already download the official iPhone Duo wallpapers in light and dark versions for your current devices.