Overview
- Apple began accepting submissions for iPhone Duo–optimized apps after releasing Xcode 27.1 Release Candidate 1 and new Device Hub tools to preview foldable layouts.
- Developers who update or recompile with Xcode 27.1 will earn an 'optimized for iPhone Duo' badge on App Store product pages once their builds are submitted.
- Apple requires Duo-specific screenshots for all App Store submissions starting April 2027, and immediate submissions must also include updated screenshots and preview assets for Duo layouts.
- App Store review still applies and may delay approvals, so developers are urged to submit early if they want apps available when pre-orders begin October 16 and devices ship October 23, 2026.
- Code exploration found a Duo Quick Look two-page spread for the unfolded view, which highlights the interface and multitasking changes apps will need to support across the device's poses.