Apple: 100,000+ apps now optimized for iPhone Duo

Apple has announced that the number of apps optimized for the iPhone Duo has passed 100,000, just two weeks after the device went on sale. According to the company, the figure covers apps built with the iOS 27.1 SDK or later, which fill the full width of both the inner and outer displays and place vertical controls in the status bar.

Susan Prescott, Apple's vice president of Worldwide Developer Relations, said the company is pleased with how quickly developers have embraced the iPhone Duo and thanked them for their creativity and innovation. Apple says thousands of optimized apps are being added to the App Store every day, and it expects the pace of updates to keep growing.

Which apps have been optimized?

Among the recently optimized examples, Apple named Microsoft's Excel, OneNote, PowerPoint and Word, as well as Etsy, Goodnotes, Halide Mark III, NBA, NHL and Zoom. Amazon Prime Video, Fantastical, Flighty, Instagram, MLB, Netflix, SmartGym, WhatsApp and YouTube are also on the list of optimized apps, which is too long to reproduce in full.

Optimized apps are marked with a "Made for iPhone Duo" badge on their App Store pages on the device, making them easy to spot. The iOS 27.2 update also added Apple Pencil (USB-C) support to the iPhone Duo. That lets users draw in apps such as Procreate Pocket, take notes in Apple Notes, Fineliner and TypeDraw, and mark up documents in apps like Preview.

Apps that haven't caught up yet

With millions of apps in the App Store, it is hardly surprising that many have not yet been updated for the iPhone Duo. Examples that are not optimized include AMC Theaters, Amazon Fire TV, Apple Store, Best Buy, Bluesky, Delta, DoorDash, Duolingo, Fandango, FedEx, Goodreads, Google Docs, Google Home, Google Sheets, Google Slides, GrubHub, JetBlue, Libby, Microsoft Authenticator, Microsoft Teams, MTA, Nike, PayPal, PictureThis, Ring, Southwest, Spectrum TV, Starbucks, Steam, Uber Eats, UPS, USPS, Venmo, Verizon, Wells Fargo, Whole Foods and YouTube Music.

How an app behaves depends on the SDK it was built with. Apps compiled with the iOS 27 SDK fill most of the inner display but avoid the status bar area along the right edge. Apps built with the iOS 26 SDK or earlier run on the iPhone Duo but appear in the middle of the inner display with wide black bars on both the left and right.

What developers need to do

Apple says adapting apps for the iPhone Duo is easy. Apps that use standard SwiftUI and UIKit components adapt to each screen automatically, with controls moving to the status bar and multi-column layouts supported on the inner display. New APIs let developers fine-tune their apps for the device's different layouts and postures.

The company said it has held more than 50 in-person workshops across 19 cities worldwide and also offers online resources such as the Apple Developer Forums. App optimization remains a topic of debate on social media: some users point to apps that still haven't been updated, while others think the problem is overstated. The picture is mixed, but apps are being updated every day and the situation appears to be improving quickly.