Health & Fitness v7.4
Does Calm work on iPhone Duo?
Mostly. Calm 7.4 is built with the iOS 27.0 SDK, so it fills most of iPhone Duo's inner display but leaves some space unused.
At a glance
- Inner display (7.6″)
- Partly adapted
- Outer display (5.4″)
- Works normally
- Built with
- iOS 27.0 SDK
- Version 7.4, read Oct 28, 2026
- iPad version
- Yes
- Layout already handles big screens
- Latest version
- v7.4
- Oct 26, 2026
- Duo in release notes
- Not yet
About Calm
Calm is made by Calm.com and first came out on the App Store in February 2013. It has 1,992,331 ratings on the US App Store, averaging 4.8 stars. Version 7.4 came out on Oct 26, 2026 and needs iOS 18.0 or later. It's free to download. Among the 27 health & fitness apps we track on the US App Store, 9 already fill the inner display, 4 are partly adapted and 14 still show black bars. By number of ratings, Calm is #5 of them.
From its App Store listing:
Calm is the #1 app for sleep, meditation, and relaxation. Find anxiety relief, stress relief, and better sleep through breathing exercises, sleep sounds, deep sleep music, and mindfulness programs for insomnia, beginner meditation, and beyond. Downloaded by 180 million people worldwide. Fall asleep faster with Sleep Stories, bedtime stories for adults narrated by Matthew McConaughey, Stephen Fry, …
On the inner display
Built with the iOS 27 SDK, the app extends across most of the inner display, but some areas stay empty. It's usable, just not polished.
In Split View
iPhone Duo is the first iPhone that can show two apps side by side, and every app takes part — including Calm. 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 7.4 is built with the iOS 27.0 SDK
Apple gives apps built with the iOS 27.0 SDK more of the inner display, with some space left over.
- : Not confirmed yet → Partly adapted — built with the iOS 27.0 SDK
Latest release notes
Version 7.4 · Oct 26, 2026
Thanks for using Calm, the #1 app to help you sleep more, stress less and live mindfully with a range of science-backed content and activities for daily mental health support. This update contains multiple bug fixes and performance improvements. Now take a deep breath and open the app to see what new daily meditations, Sleep Stories, soundscapes, music, breathing exercises, and more are waiting for you.
Questions
Does Calm work on iPhone Duo?
Mostly. Calm 7.4 is built with the iOS 27.0 SDK, so it fills most of iPhone Duo's inner display but leaves some space unused.
Does Calm 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 Calm 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 Calm 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 Calm 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 Calm within about a day of its release and update this page.
What can I do about the black bars until then?
Use Calm 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.