Everything the fold changes.
Short, sourced explainers — no hype, just what you need to know.
Explainer
Why some apps have black bars on iPhone Duo
Apps built with the iOS 26 SDK or earlier run in a phone-sized window with black bars on iPhone Duo’s inner display. Why, and when the bars go away.
ReadHow to
How Split View works on iPhone Duo
Two apps side by side on the inner display, in landscape, always half and half. How to start Split View, save an app pair, and what it can’t do.
ReadBefore you buy
Will your apps work on iPhone Duo? A quick checklist
Yes, every iPhone app runs on iPhone Duo. Apps not updated yet show black bars on the inner display. Check the apps you rely on in five minutes.
ReadRoundup
The best apps for iPhone Duo
Apps that are confirmed to use iPhone Duo’s inner display well — updated as new evidence arrives.
ReadGames
Gaming on iPhone Duo: what to expect
Most popular games still show black bars on iPhone Duo’s inner display. Which games are optimized, whether a game can use both screens, and controllers.
ReadFeature
StandBy on iPhone Duo, explained
Yes, iPhone Duo has StandBy: fold it like a tent for the outer display or a half-open book for the inner one, plugged in or not. How to set it up.
ReadDevelopers
Preparing your app for iPhone Duo: the short version
The SDK tiers, the new APIs, the App Store badge, and a practical order of work for getting your app off the black bars.
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