Guide · Updated
How to check if an app supports iPhone Duo
Three ways to tell whether an app is ready for the iPhone Duo inner display: check its last update date, read its release notes, or look it up on FoldCheck.
1. Look at the date of the last update
Open the app in the App Store and scroll to Version History. If the latest version is from before October 5, 2026, the app can't be built for iPhone Duo yet and will be letterboxed on the inner display.
A newer date is a good sign, but not proof, because developers can still ship updates built with an older SDK.
2. Read the release notes
Developers who add Duo support usually say so. Look for "iPhone Duo", "foldable" or "inner display" in the What's New text.
3. Search it on FoldCheck
Search any app at the top of this page. We combine the build date, the release notes and reports from Duo owners into one verdict for folded, unfolded and half-open use.
If nobody has reported an app yet and you own a Duo, your report sets the first status for everyone.