Apple says well over 100,000 iPhone Duo apps are now live on the App Store, roughly two weeks after the phone went on sale. The number came in a statement from Susan Prescott, Apple’s vice president of Worldwide Developer Relations, who added that thousands more optimized apps arrive every day.
If you have a Duo in hand, that is the first hard figure on whether your home screen will stop looking letterboxed. It is also a figure that says nothing about which apps are inside the count, and that is the part that decides your day.
TL;DR: Apple says well over 100,000 apps built for the iPhone Duo are live, with thousands more added daily. The figure is Apple’s own, and it tracks apps rebuilt with the iOS 27.1 SDK or later. Popular apps such as Google Docs, Venmo and Starbucks are still not optimized, so the total does not mean your daily apps are ready.
What Apple said about iPhone Duo apps
In its statement, published by 9to5Mac, Apple said “well over 100,000 apps built for iPhone Duo” are already live and that “thousands of optimized apps are being added to the store each day.” Prescott also said developers have joined Apple workshops in 19 cities over the last month.
Apple did not attach a list or a breakdown to the number, so there is no outside check on it. The App Store holds millions of apps, which means 100,000 is a large figure and still a small slice. A big total can leave your most used app untouched, and that gap is what the rest of this piece is about.
How an app counts as optimized
Apple’s developer guidance for the iPhone Duo sorts apps by the SDK they were built with. The tier an app lands in decides how it looks on the inner display.
| Built with | What happens on iPhone Duo |
|---|---|
| iOS 26 SDK or earlier | Runs, but sits centered on the inner display with empty space around the window |
| iOS 27 SDK | Fills most of the inner display but avoids the status bar on the right edge |
| iOS 27.1 SDK or later | Optimized, edge to edge on both displays |
Developers who submit Duo screenshots in App Store Connect get a badge on their product page showing the app is optimized. MacRumors reports that Apple’s count covers apps built with the iOS 27.1 SDK or later, which fits that top tier.
That definition is why the count moves in steps. An app only joins it when its developer rebuilds and ships an update, and our piece on Duo split view found results already vary by the SDK an app was built with.
Which apps are still missing
The same MacRumors report lists apps it found optimized, including Netflix, Instagram, WhatsApp, YouTube, Zoom, Word, Excel, Flighty and Prime Video. It also lists examples that are not, among them Google Docs, Google Sheets, Venmo, PayPal, Starbucks, DoorDash, Delta and Wells Fargo.
Look at that second list and the pattern is plain. Banking, payments, food ordering and airline apps are the ones people open daily, and they are the ones still without the optimized layout. Opening your bank app on a $1,999 phone and seeing a window floating in the middle is a small insult, but it is the one you will notice.
The practical check is cheap. Before you download or rely on an app, look for the optimized badge on its App Store page, and expect an unbadged app to keep its black margins until its developer ships a rebuild.
What to watch as the count climbs
Apple said the pace of updates should keep accelerating, and there is no reason to doubt the direction. The open question is the order. Developers will likely rebuild the apps with the most Duo owners first, and with supply tight, that audience stays small for a while.
So the useful number to track is not the total but whether the five or six apps you open every day carry the badge. Check them one by one when updates land, because the 100,000 figure will keep growing long before that list is finished. The SDK arrived with iOS 27.1, which is a Duo only release.
