Health & Fitness v9.1.100
Does Keep work on iPhone Duo?
It works, but with black bars. Keep 9.1.100 is built with the iOS 26.2 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 26.2 SDK
- Version 9.1.100, read Nov 3, 2026
- iPad version
- Yes
- Layout already handles big screens
- Latest version
- v9.1.100
- Nov 2, 2026
- Duo in release notes
- Not yet
About Keep
Keep is made by Keep and first came out on the App Store in February 2015. It has 16,538 ratings on the US App Store, averaging 4.8 stars. Version 9.1.100 came out on Nov 2, 2026 and needs iOS 14.0 or later. It's free to download.
From its App Store listing:
Keep 9.1 全新升级，越练，越懂，越健康！ 在 Keep，与 4 亿运动爱好者共同见证专业与科技的完美融合。Keep 9.1 继续围绕 AI 运动教练体验进化：从训练安排、健身记录、跑步陪伴，到吃练睡数据解析与身体状态洞察，让每一次运动都更清晰、更有反馈。 基于 Keep 运动健康大模型 Keepace.ai，AI 教练更懂你的训练节奏与身体变化。无论你是在家跟练、户外跑步，还是在健身房进行力量训练，Keep 都将陪你更科学地运动，也更深入地了解自己。 你是否也曾遇到这些困扰： - 想在家运动，空有热情但无从下手？ - 想跟练课程，却无法根据自己的需求做出选择？ - 在健身房训练时，器械、组数、重量、次数总是不好记录？ - 跑步计划难以坚持，希望有人在过程中提醒、反馈和陪伴？ - 吃、练、睡数据散落各处，看不懂背后的身体变化？ - 想了解自己的身体状态，却缺少一个更直观的参考？ - …
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 Keep. 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 9.1.100 is built with the iOS 26.2 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 26.2 SDK
Latest release notes
Version 9.1.100 · Nov 2, 2026
Keep 9.1 全新升级，越练，越懂，越健康 - AI 语音互动跑：边跑边聊，AI 在过程中给你反馈、提醒和鼓励，边跑边陪伴。 - 健身记录工具升级：支持记录健身房训练轻松记录，让力量训练更清晰。 - AI 深度数据解析：围绕吃、练、睡进行更全面的数据解读，帮你看懂身体状态与生活习惯的变化。 - 身体年龄解析：助你了解自己的身体状态，找到更适合自己的训练方向。 - 超级 AI 会员正式上线：从训练建议到数据洞察，更完整的 AI 运动服务，更智能、更个性化的运动支持。 Keep 9.1，不止运动，更陪你成为更健康的自己。
Questions
Does Keep work on iPhone Duo?
It works, but with black bars. Keep 9.1.100 is built with the iOS 26.2 SDK, so iPhone Duo runs it in a phone-sized window on the inner display.
Does Keep 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 Keep 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 Keep 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 Keep 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 Keep within about a day of its release and update this page.
What can I do about the black bars until then?
Use Keep 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.