Apple’s first foldable iPhone, the iPhone Duo, introduces software designed around its two-screen form factor, while still running iOS. Its main significance is bringing iPad-style multitasking to an iPhone, allowing two apps to run side by side on the inner display, alongside interface changes tailored to the larger screen.

The Duo also supports Apple Pencil input, fold-specific layouts, tent mode, hinge-aware controls and a redesigned status bar with indicators, the Dock and Dynamic Island arranged along the side. Exclusive camera features include AI-assisted Smart Take, external-screen previews, Kid Cue and simultaneous front- and rear-camera FaceTime; however, it lacks some of the iPhone 18 Pro’s advanced camera functions.