Health & Fitness v3.54.0
Does Mi Fitness (Xiaomi Wear Lite) work on iPhone Duo?
It works, but with black bars. Mi Fitness (Xiaomi Wear Lite) 3.54.0 is built with the iOS 26.4 SDK, so iPhone Duo runs it in a phone-sized window on the inner display.
At a glance
- Inner display (7.6″)
- Black bars
- Outer display (5.4″)
- Works normally
- Built with
- iOS 26.4 SDK
- Version 3.54.0, read Oct 29, 2026
- iPad version
- Yes
- Layout already handles big screens
- Latest version
- v3.54.0
- Oct 28, 2026
- Duo in release notes
- Not yet
About Mi Fitness (Xiaomi Wear Lite)
Mi Fitness (Xiaomi Wear Lite) is made by Beijing Xiaomi Co., Ltd and first came out on the App Store in July 2020. It has 40,081 ratings on the US App Store, averaging 4.6 stars. Version 3.54.0 came out on Oct 28, 2026 and needs iOS 14.0 or later. It's free to download.
From its App Store listing:
Combining Mi Fitness with smartwatch or smartband devices, users can track their health and fitness data. Mi Fitness supported：Xiaomi Watch Series, Redmi Watch Series, Xiaomi Smart Band Series, Redmi Smart Band Series. Keep track of your workouts Map your route, monitor your progress, and achieve your goals. Whether it's walking, running, or biking, you can easily track it right from your phone. M…
On the inner display
Apps built with older SDKs are placed in a phone-sized safe area on a black background. Everything works; you just don't get the bigger screen.
In Split View
iPhone Duo is the first iPhone that can show two apps side by side, and every app takes part — including Mi Fitness (Xiaomi Wear Lite). Open it on the inner display, then add a second app next to it. You can save the pair and come back to it later.
Duo-specific features
None confirmed yet. Duo-specific features include side toolbars, layouts that react to the fold, and content on the outer display while the app is open inside.
Evidence & history
App build,
Version 3.54.0 is built with the iOS 26.4 SDK
Apple runs apps built with the iOS 26 SDK or earlier in a phone-sized window on the inner display.
- : Not confirmed yet → Black bars — built with the iOS 26.4 SDK
Latest release notes
Version 3.54.0 · Oct 28, 2026
1. Improved the flow for enabling cloud sync for sleep factors 2. Fixed an issue with Morocco's time zone on some devices 3. Fix some bugs
Questions
Does Mi Fitness (Xiaomi Wear Lite) work on iPhone Duo?
It works, but with black bars. Mi Fitness (Xiaomi Wear Lite) 3.54.0 is built with the iOS 26.4 SDK, so iPhone Duo runs it in a phone-sized window on the inner display.
Does Mi Fitness (Xiaomi Wear Lite) work on the outer display?
Yes. iPhone Duo's 5.4-inch outer display behaves like a regular iPhone screen, so every iPhone app works there as usual.
Can I use Mi Fitness (Xiaomi Wear Lite) in Split View on iPhone Duo?
Yes. On iPhone Duo every app can be placed side by side with another app on the inner display — developers don't need to opt in. How comfortable it feels at half width depends on the app's layout.
Why does Mi Fitness (Xiaomi Wear Lite) have black bars on iPhone Duo?
Apps built with the iOS 26 SDK or earlier run in a phone-sized window on the inner display, and iOS 27 builds can still leave some space empty. The bars disappear once the developer rebuilds the app with the iOS 27.1 SDK — you only need to update the app.
When will Mi Fitness (Xiaomi Wear Lite) fill iPhone Duo's inner display?
When its developer releases an update built with the iOS 27.1 SDK or later. We read the SDK of every new version of Mi Fitness (Xiaomi Wear Lite) within about a day of its release and update this page.
What can I do about the black bars until then?
Use Mi Fitness (Xiaomi Wear Lite) on the outer display, where it works like on any iPhone, or put it in Split View next to another app on the inner display so less of the screen goes unused.