DuoDiscoverA place to discover apps for Duo.
DuoDiscover is an independent directory of iPhone Duo apps.
iPhone Duo (rumored before its announcement as the iPhone Fold) is Apple’s first foldable iPhone, with a 7.6-inch inner display, a 5.4-inch outer display and iOS 27.1. Every App Store app runs on it, but only some make use of the larger screen or the fold. DuoDiscover lists those apps, says what each one does on the Duo, and shows how and when that was checked.
DuoDiscover is not affiliated with, endorsed by or sponsored by Apple.
The three tiers
Every app is labelled compatible, adapted or optimized. Optimized apps carry the Built for Duo label. The compatibility guide explains the difference in more detail.
- Built for Duo
- Also called Made for iPhone Duo. Does something specific with the hardware: a different layout folded and unfolded, Split View, the half-open position or the outer display.
- Adapted
- Rebuilt with the iOS 27 SDK or later, so it resizes to the 7.6-inch inner display instead of showing black borders. With the iOS 27.1 SDK it can use the whole screen.
- Compatible
- Runs unchanged. It looks normal on the outer display and keeps its phone layout, with black borders, when unfolded.
How we review apps
Every listing is reviewed by hand before it is published, and records one of three verification methods:
- Developer statement: the developer confirmed the app’s support, for example in release notes or a public post.
- Simulator: tested in the iPhone Duo simulator in Xcode 27.1.
- On device: tested on an iPhone Duo.
The date and method appear on each app page. When an app changes, the listing is checked again and the date updated.
Spot a mistake? Post in r/iPhoneduoapp and the listing will be corrected.
NostalgicPod, the first app listed, is made by the creator of DuoDiscover. It follows the same review rules as every other listing.
Community
Discussion happens in r/iPhoneduoapp.
Submit your app
Post it in r/iPhoneduoapp. See how to submit your app.
FAQ
Which apps are optimized for iPhone Duo?
Apple has named Netflix, Zoom, Slack and Detail as day-one partners and publishes no wider list. DuoDiscover tracks apps in three tiers: Built for Duo (use the fold, Split View or the outer display), Adapted (rebuilt with the iOS 27 SDK or later to fill the inner display) and Compatible (run unchanged). Every listing shows how and when it was verified.
Do all iPhone apps work on iPhone Duo?
Yes. Every App Store app installs and runs on iPhone Duo. Apps built with the iOS 26 SDK or earlier look normal on the outer display but keep their phone layout when unfolded, with black borders on the 7.6-inch inner screen. Apps rebuilt with the iOS 27 SDK resize to fill most of it, and with the iOS 27.1 SDK or later all of it.
Does the App Store show which apps are optimized for iPhone Duo?
No. The App Store has no iPhone Duo filter or badge, so there is no official way to browse optimized apps. DuoDiscover is an independent directory that lists them by hand, with the date and method of each check.
Why do some apps have black bars on iPhone Duo?
Apps built with the iOS 26 SDK or earlier keep their phone layout when iPhone Duo is unfolded, so they appear with black borders on the 7.6-inch inner display. Once the developer rebuilds the app with the iOS 27 SDK or later, it resizes to fill the screen.
How does an app get listed?
Post it in r/iPhoneduoapp with the App Store link and unfolded screenshots. Each app is checked by hand before it is published.