Apple's first foldable iPhone turns its 7.6-inch inner display into a two-page reader. Opened flat, a PDF or an ebook spreads across both halves, one page on each side, like holding a real book. Hands-on videos from creators show a book-like reading mode on iPhone Duo with a page-turn animation that mimics paper, a small but telling detail about how seriously Apple takes the reading experience.
This is not a stretched iPhone interface. iOS 27.1, which ships on the Duo, adapts in real time to the fold angle: content shifts away from the crease where taps are harder to register, and app layouts reconfigure as the device opens, closes, or sits half-folded. Apple gave the 5.4-inch outer display and the 7.6-inch inner display the same aspect ratio, so the interface appears to come into focus as it moves between screens rather than jumping abruptly. According to Apple, building this required rethinking how every app lays out content as the screen changes shape, including moving the Dock to a vertical orientation along the side.
Split View puts two apps side by side on one iPhone screen, something no iPhone has ever done. Users can run two apps at once, open two windows of the same app — Apple uses two Safari windows for comparison shopping as the example — or keep Siri AI open on one side while content stays visible on the other. Commonly used app pairs can be saved and reopened in one tap, and drag and drop works across the hinge. Apple also demonstrated Zoom showing shared content and participants simultaneously, and Slack expanding to show more of its workspace.
Apple's new CEO John Ternus, who took over from Tim Cook on September 1, unveiled the Duo on September 9 in Cupertino, calling it "the most transformational change to iPhone since the original." At $1,999 it is the most expensive iPhone yet, though analysts note it costs less than some had feared. The Duo ships with iOS 27.1 — the iPhone 18 Pro gets iOS 27.0 on September 14 — with pre-orders starting Friday, October 16 and availability on Friday, October 23. Singapore pricing starts at S$3,099 for the 256GB model.
Apple has already added "Designing for iPhone Duo" to its Human Interface Guidelines, with fuller developer documentation promised later this month. Apple Pencil (USB-C) support on both displays is slated for later in 2026. Foldables still account for less than 5% of the smartphone market, per CCS Insight, but analyst Ben Wood says the Duo's price could help pull foldables toward the mainstream. Whether people keep unfolding the device six months from now will come down to the software — and on that front, Apple has put its whole weight behind making the big screen genuinely useful.