iPhone Duo Apps Not Optimized Yet: A Running List

Updated October 22, 2026. This page tracks which planner and productivity apps are confirmed for iPhone Duo’s inner display, and it changes as more ship support. Checking it before you install something saves you from assuming an app does more than it does.

iPhone Duo goes on sale October 23, and most of the apps on your phone today were written before the inner display existed. Some are ready. Many are not, yet.

What an unoptimized app looks like

According to 9to5mac, an app that has not been updated for iPhone Duo runs in a centered window with black borders on either side when the phone is open, rather than filling the 7.6 inch inner display that Apple says (Apple) is 50 percent larger than iPhone 18 Pro Max.

The app still works. You can tap, scroll and type exactly as you would on a regular phone. It just sits in the middle of a bigger screen instead of using it, which is iOS being honest about a layout nobody has adapted yet.

The badge that tells you an app is ready

9to5mac reports that a build compiled on Apple’s 27.1 SDK earns an optimized badge, visible inside the app or in its App Store listing. That badge is the clearest signal a developer has specifically targeted the inner display, rather than just letting an old build run unchanged.

How to check any app yourself

1. Open the app’s page on the App Store and look for iPhone Duo screenshots, shown closed and open.
2. Open the app itself on iPhone Duo and look for the optimized badge.
3. Watch what happens when you open the phone. A real update adds a second panel or more detail. An old build just gets wider, with black borders on both sides.

We only add an app to the table below once we have confirmed its iPhone Duo support on the app’s own page that day.

Planner and productivity apps and their iPhone Duo status

App	iPhone Duo status
PathRank	Built for iPhone Duo. Its iPhone Duo version is on its way to the App Store.
Slack	Confirmed support, named in Tom’s Guide’s roundup of apps ready for iPhone Duo and listed as a launch partner on FoldHunt.
Zoom	Confirmed support, named in Tom’s Guide’s roundup of apps ready for iPhone Duo and listed as a launch partner on FoldHunt.
Netflix	Confirmed support, named in Tom’s Guide’s roundup of apps ready for iPhone Duo and listed as a launch partner on FoldHunt.

On October 21, FoldHunt named four launch partners ready on day one: Netflix, Detail, Slack and Zoom. Detail is a video app, so it is not in the planner table above. FoldHunt also tracks 1,037 apps and games with dated evidence for each listing, and its October 21 check sorted them into 4 launch partners, 72 simulator verified, 834 developer claimed and 127 not announced, so it is the place to look up an app this page does not cover. A developer claim is not a confirmation, which is why this table stays shorter than that count.

We leave an app off this table until we can confirm its status ourselves, so the list is shorter than the number of apps that may already work well. If you use an app daily and do not see it here, run the three checks above yourself.

Why this list stays short on purpose

It would be easy to guess which apps probably support iPhone Duo based on their size or their developer’s reputation, but a guess is not a confirmation. This page only adds an app once its own App Store page or its developer’s own announcement states iPhone Duo support on the day we check, the same standard we hold every claim on this site to.

That means the table above will look thin for a while after launch, even though plenty of other apps may already work well on the inner display without having said so publicly yet. If you cannot find confirmation for an app you use, treat its status as unknown rather than assuming either way, and run the checks yourself.

What an unconfirmed app usually means in practice

Most apps without a confirmed update are not broken, they simply have not published anything about iPhone Duo yet. An app running in the centered window described above should still work normally for tapping, scrolling and typing, since that window is just a smaller version of the same app. The apps worth watching closely are the ones you rely on every day, since those are where a missing update is most noticeable.

A worked example: checking your own home screen

Pick your five most used apps and run the checks in order. Say your five are a messaging app, a planner, a browser, a video app and a notes app. Open each one, then open the phone while it is running.

Your messaging app likely looks the same open or closed, since a conversation is one column either way. Your browser probably just shows a wider page, which is still useful even without a dedicated layout. Your planner and notes app are where the difference is biggest: an updated one shows you more structure, a goal and its steps, or an outline next to the page, while an unoptimized one sits in a centered window with black borders.

Running this check across your own home screen takes about ten minutes and tells you exactly where iPhone Duo will change your day one, and where you will not notice a difference yet.

Where PathRank stands

PathRank is built for iPhone Duo, with a layout for the outer display and one for the open inner display. Closed, it works like the phone app: brain dump by voice or text, see your next Ready task, check things off. Open, the plan continues across the larger display with the same navigation in the same place.

Behind that layout, PathRank turns a goal into a World with a Monster goal at the top and steps sorted into Ready, Prep, Research and Blocked phases, with a date only on what you can do now. Its iPhone Duo version is on its way to the App Store, and the phone app is live today on iOS and Android.

Check back as this list grows

More planner and productivity apps will confirm iPhone Duo support in the weeks after launch, and we will add each one here once we have verified it ourselves. For the criteria behind every row on this page, read our guide to iPhone Duo apps. Every PathRank guide for the new phone lives on the iPhone Duo hub.