Will your apps work on iPhone Duo? A quick checklist

iPhone Duo starts at $1,999 and went on sale on October 23, 2026. Every iPhone app runs on it — the question is how the apps you use most look on the 7.6-inch inner display. Here’s how to check in five minutes.

The short answer

On the outer display, everything works like on any iPhone. On the inner display, apps are shown full screen, partly adapted, or with black bars, depending on when they were last rebuilt. Here’s why. Right now, 35 of the 100 most popular apps we track are confirmed to fill the inner display.

A five-minute checklist

1. List the five apps you open most. Look up each one on WorksOnDuo — the answer is the first line of every page.
2. Check the App Store. Optimized apps carry a Made for iPhone Duo badge on their product pages.
3. Check for an iPad version. Each app page shows it. Apps that already run on iPad have layouts designed for big screens and tend to adapt faster.
4. Look at the last update date. Apps updated every week or two are more likely to ship iPhone Duo support soon.
5. Decide which apps need the big screen. Banking, ride-hailing or delivery are quick tasks you’d do on the outer display anyway. Video, reading, email and documents are where black bars would bother you.
6. Get notified. Follow the recently updated list or subscribe to its RSS feed.

What reviewers found at launch

Reviewers tested iPhone Duo in the week before launch. Apple’s own apps were ready, but most third-party apps weren’t optimized yet. Apps were updating daily: Slack, Instagram, Threads and the Google app gained full iPhone Duo layouts during that week. Apple has named more than 50 third-party apps that are optimized now or coming soon, and says more updates will roll out throughout the year.

Banking apps

Banking apps are the most common worry. They tend to update cautiously and many have no iPad version, so expect black bars on the inner display for a while. None of the launch reviews reported a banking app that didn’t work, and they work normally on the outer display.

All banking & finance apps

Apple’s own apps are ready

Apple’s built-in apps — Mail, Photos, Safari, Camera, FaceTime, Notes and Music among them — have been optimized for iPhone Duo, and Apple showed Netflix, Zoom, Slack and Detail already using the larger display. See the best apps for iPhone Duo.

Bottom line

If your most important apps are video, reading or productivity apps with iPad versions, iPhone Duo should feel great early on. If you mostly live in phone-only apps, expect a few weeks — sometimes months — of black bars on the inner display, with everything working normally when closed.