DuoKits

Every App Store app runs on iPhone Duo, but most just show their phone layout with black borders on the 7.6-inch inner screen, and the App Store doesn't say which ones do more. DuoKits is a directory built to answer that one question. Its homepage counted 1,506 listed apps across 14 categories in late October 2026, 156 of them marked Built for Duo.

That label is the interesting part. Built for Duo means the app does something with the hardware, such as switching layout when you unfold it, using Split View, working half-open or using the outer display. Listings with the label include YumYums, a recipe manager, and Fold Prison, a game where folding the phone locks cartoon inmates in their cells. Adapted apps were rebuilt with the iOS 27 SDK so they fill the inner display without borders, and Compatible apps run unchanged.

What makes DuoKits more useful than a list of app names is that it shows its work. Each listing names how its status was established, whether from a developer statement, an Apple announcement, a test in the Xcode simulator or a test on an actual iPhone Duo, and gives the date of that check. The about page says outright that a source claim is not a real-device test. Apps without enough evidence for a tier are marked Claimed support or Pending verification instead of being rounded up.

Listings can't be bought, and the site says a tier can't be paid for. Developers can submit apps for free, and submissions are reviewed before they appear.

A launch tracker follows which apps Apple and developers have confirmed for the device, with sources, including Netflix, Zoom and Slack. An ideas section collects concepts for hinge-based apps, like a pinball game where opening and closing the phone works the flipper. There are wallpapers for both screens, with widgets listed as coming soon.

The whole directory is also published as open data at /apps.json, with each app's tier, price, verification date and source, plus an RSS feed. DuoKits is independent and not affiliated with Apple.