Foldable phones have always lived or died by their apps, and iPhone Duo is getting off to a strong start. Only weeks after launch, developers have moved quickly to rework their software for Apple’s new form factor. The result is an app library that already looks far more mature than most first-generation foldables have managed.
Apple says more than 100,000 apps built for iPhone Duo are now available on the App Store, with thousands of newly optimized titles added every day. Susan Prescott, Apple’s vice president of Worldwide Developer Relations, says developers have “embraced iPhone Duo” quickly. She points to recent hands-on workshops in 19 cities as one reason the pace of updates keeps picking up.
Part of that speed comes from groundwork Apple laid earlier. Any app that already supports iOS 27 and resizable iPhone layouts can use the larger inner display immediately. Owners didn’t have to wait months for basic compatibility, a problem that held back earlier foldables on other platforms.
The headline names are already in place. Apple says Netflix, YouTube, Instagram and WhatsApp were optimized from day one. Microsoft has brought a desktop-class version of Word and Outlook to the phone, and Zoom turns the inner screen into a fuller video meeting space. Sports fans get more room for NBA and NHL games and highlights, while Etsy and LTK Creator fit more products into every scroll. Halide Mark III shows how creative developers can get: it gives you a clean viewfinder on the cover screen when closed and a waist-level shooting mode when the phone is half open.
Most of the adaptation work is handled by Apple’s own frameworks. Apps built with standard SwiftUI and UIKit components in the iOS 27.1 SDK automatically move controls within reach and spread content into multiple columns. They also keep buttons clear of the crease when the device is partially folded. New APIs let developers split layouts across the fold or respond to the hinge angle as the phone opens and closes.
iOS 27.2 adds Apple Pencil (USB-C) support. That opens the door to sketching in Procreate Pocket, handwritten notes in Fineliner and Apple Notes, and document markup in Preview, which pushes iPhone Duo into territory normally reserved for the iPad.
Apple says more than 2,000 developers have attended over 50 in-person workshops so far, with sessions still to come in London, Paris, Toronto, Montreal and Mexico City. New App Store collections and a “Made for iPhone Duo” badge make optimized apps easy to find. With this much momentum this early, the bigger question is how far developers will push the fold once the basics are covered.