Apple is preparing a new Made for iPhone Duo label for the App Store. It will go to apps and games that genuinely use the larger area of the foldable phone instead of simply stretching their usual interface.
The reason is clear: outside Apple's own software there are few adapted apps so far, and many of them look rough on the new device.
What proper adaptation looks like
Apple gave examples. Netflix plays video across the whole inner screen and keeps a short-video feed on the outer one. Prime Video, with the phone partly folded, shows the film on top and cast details below. Word places formatting tools next to the document, Outlook shows the inbox next to the open message, and Zoom displays participants and shared content at the same time.
Curated collections of optimized apps are due in the App Store on Friday and will be refreshed throughout the year. Even so, according to The Verge, testers found bugs in some of the listed apps.
Where developers struggle
Many third-party apps open on the iPhone Duo with black bars at the edges. Part of the reason is how iOS works: interfaces scale to predefined resolutions and aspect ratios, while Android's adaptive layouts adjust more flexibly to any window size. The outer screen's unusual 14.5:10 ratio makes things harder.
On top of that, Apple took part of the screen width for a new taskbar. Apps that ignore it leave that area empty on both the outer and inner displays.
Our take
Anyone who builds websites knows this story: fixed layouts made for a couple of sizes break as soon as a new device appears. If an interface is built on a flexible grid from day one and can reflow into two columns, a foldable screen becomes a bonus rather than a headache. Details in the 3DNews article.