Every app worth opening on both screens of iPhone Duo.
We test, rank, and explain the apps, tools, and settings built for iPhone Duo's fold — plus plain-English tutorials for getting the most out of dual-screen multitasking.
What is iPhone Duo, and why does it need its own app guide?
iPhone Duo is Apple's foldable iPhone, built around a single 7.6-inch inner display that folds flat into a pocketable device with a 5.4-inch outer display. That hinge changes how software should behave: an app that hasn't been rebuilt for it just runs boxed in with black bars, while an app designed for the fold can turn Split View's second pane into a real workspace — a sketch app can keep your reference photos off the canvas, a calendar app can accept a task dragged straight off your to-do list.
Apps for Duo exists because most App Store listings don't tell you which of those two categories an app falls into. We research and write up every app and update with the fold specifically in mind, cross-checking claims against Apple's own developer documentation, and publish plain-English tutorials for getting more out of Duo's multitasking, settings, and developer tools. Coverage published before launch is clearly labeled as pre-launch research rather than hands-on testing — Apps for Duo is not affiliated with, endorsed by, or sponsored by Apple.
Start here
- Browse the iPhone Duo apps directory
Every app we've researched, ranked by fold quality.
- Read setup guides and reviews
Tutorials, workflows, and researched guides.
- Building for Duo? Start with iOS 27
Our developer guide to the current beta stack.
Editor's picks
Apps that make the most of the fold.
From the Learn hub
Reviews, tutorials, and Duo news.
Will the crease be visible on iPhone Duo? What the nano-texture finish actually does
The most common question we are seeing ahead of launch. Here is what Apple has said, what early hands-on impressions suggest, and what is still unverified.
Sep 21, 2026
iOS 27, Xcode 27.1 beta, and macOS Tahoe 26.6: what Duo developers need to know
A practical rundown of the current developer beta stack for iPhone Duo: what's new in iOS 27 for dual-screen apps, what Xcode 27.1 beta requires, and why macOS Tahoe 26.6 matters for your build machine.
Sep 21, 2026
5 Split View workflows worth setting up on your iPhone Duo this week
Most people use a fraction of what iPhone Duo's fixed 50/50 Split View can actually do. Here are five workflows we set up on day one and still use every day.
Sep 18, 2026