Guides
Practical answers about apps on iPhone Duo, for owners and for developers.
For owners
How to tell if an app is optimized for iPhone Duo
A smaller window, a stretched layout or a real two-pane design: how to check in a few seconds whether an app is ready for iPhone Duo's inner display, and what to do if it isn't.
Updated October 12, 2026
For developers
Getting your app ready for iPhone Duo: a developer checklist
Rebuild with Xcode 27.1, test every posture, ship before October 23 and plan for the April 2027 screenshot rule. A practical checklist with links to Apple's announcements.
Updated October 12, 2026