ABOUT DUO TRACKER
About this site
Last updated: October 22, 2026
Duo Tracker is an independently maintained iPhone Duo app compatibility directory: a record you can check line by line for whether the apps you use actually work on the unfolded screen.
What the site does
Apps are tracked by App Store region: the top 200 free apps in Mainland China, the top 100 in the United States, plus the top 50 in every official Apple category for both regions, deduplicated by App ID. Each entry records the store version, the tested version, the iOS version, a manual check note and a direct App Store link.
Where the data comes from
App names, icons, rankings and store versions come from Apple's public App Store charts and store pages. Metadata and icons are collected during maintenance, so visitors never trigger cross-origin requests to Apple. Chart refreshes update public data only and never overwrite manual verification results.
How compatibility is decided
The four states are adapted, partially adapted, not adapted and not checked. Results come from manual checks of main layouts, fold transitions and core tasks, and are tied to a specific app version and iOS version. A new store release does not inherit an old result, and when evidence is insufficient the status stays not checked instead of being guessed.
What you can find here
The app directory (Mainland China / United States × Chinese / English), a recommended list curated from personal picks and feedback, a method page explaining the four states, and a privacy notice. Every page is prerendered static content, so the directory and App Store links still work without JavaScript.
Why this site exists
A foldable screen changes the aspect ratio, and many apps are simply stretched rather than adapted: split views, empty space, landscape layouts and the transition between folded and unfolded states all expose problems. That experience is scattered across release notes, forums and personal testing, which makes it hard to tell whether an everyday app is usable right now. This record exists to answer that question.
Independence and disclaimers
The site is independently maintained by an individual and is not affiliated with Apple Inc. It is not an official endorsement by any app developer. App names and icons belong to their respective owners. The recommended list reflects the maintainer's personal preference and feedback data, and compatibility may change after app updates.
Feedback and updates
If an app is missing or you have hands-on experience, share it through the Feishu feedback form linked on this site. Charts and versions update with each data refresh, while manual results are published after the maintainer confirms them.
Help complete the compatibility record
Missing an app or have hands-on experience? Share it through our Feishu form.