# FoldReady
> iPhone Duo app compatibility consulting and automated foldable testing. Get your iOS app ready for iPhone Duo and foldable devices. Fixed-price Duo readiness audits, redesign and implementation, and FoldCheck, an automated compatibility tester for every fold pose.

Contact: vity5.diduk@gmail.com. Updated: 2026-09-12.

## iPhone Duo key facts
- Announced: September 9, 2026
- Ships: October 23, 2026
- Starting price: $1,999
- Outer display: 5.4 inches, 1398 x 2034 px, 460 ppi, compact width
- Inner display: 7.6 inches, 1878 x 2670 px, 430 ppi, regular width and height
- Poses to support: Six: closed, open and half folded, each in portrait and landscape; plus side-by-side multitasking
- Legacy apps: Apps built with an SDK older than iOS 27 run letterboxed; iOS 27 extends content past the status bar, iOS 27.1 reaches the screen edge
- Required tooling: Xcode 27.1, iOS 27.1 SDK, Device Hub simulator
- New layout API: ReservedRegion (SwiftUI) / UIViewReservedRegion (UIKit), kinds: division (fold), occlusion (camera)

## Services
- iPhone Duo readiness audit: every screen tested in all poses, prioritized fixes, delivered in five business days. Fixed price. https://foldready.dev/#services
- Redesign and implementation: size-class layouts, ReservedRegion work, half-fold and multi-window behavior, shipped as pull requests. https://foldready.dev/#services
- FoldCheck: automated iPhone Duo and foldable compatibility tester, early access. https://foldready.dev/#foldcheck

## Guides
- [How to prepare your iOS app for iPhone Duo: a 12-step checklist](https://foldready.dev/guides/prepare-your-app-for-iphone-duo): A practical checklist for making an existing iOS app work well on iPhone Duo before its October 23, 2026 launch: size classes, ReservedRegion, safe areas, poses, multitasking and testing in the Xcode 27.1 simulator.
- [iPhone Duo specs for developers: displays, size classes, poses and tools](https://foldready.dev/guides/iphone-duo-specs-for-developers): The iPhone Duo facts that matter when adapting an app: outer and inner display sizes and resolutions, size classes per pose, the fold and camera reserved regions, SDK versions and simulator tooling.
- [SwiftUI and UIKit layouts for iPhone Duo: size classes, split views and reserved regions](https://foldready.dev/guides/swiftui-uikit-layouts-for-iphone-duo): Code-level guidance for adapting SwiftUI and UIKit layouts to iPhone Duo: reading size classes, using NavigationSplitView, dropping UIScreen.main.bounds, and respecting the fold and camera reserved regions.
- [iPhone Duo testing checklist: the pose matrix every screen must pass](https://foldready.dev/guides/iphone-duo-testing-checklist): A QA matrix for iPhone Duo and foldable devices: which poses and size classes to test, what visual defects to look for, how to use the Xcode 27.1 simulator, and how to automate the run.
- [iPhone Duo app letterboxed or not full screen: why it happens and how to fix it](https://foldready.dev/guides/iphone-duo-app-letterboxed-fix): Why an existing iOS app shows black bars or does not fill the inner display on iPhone Duo, and the exact steps to fix it: rebuild with Xcode 27.1, adopt size classes, remove fixed dimensions and handle reserved regions.
- [How much does it cost to update an app for iPhone Duo?](https://foldready.dev/guides/iphone-duo-app-update-cost): Realistic effort and cost ranges for making an iOS app work well on iPhone Duo, by app type, with the factors that move the estimate up or down and what a fixed-price audit covers.
- [iPhone Duo support for React Native and Flutter apps](https://foldready.dev/guides/react-native-flutter-iphone-duo): What cross-platform iOS apps need for iPhone Duo: window dimensions that update on fold and unfold, safe areas around the fold, size-class equivalents, and where native code is still required.
- [iPhone Duo design guidelines for product teams](https://foldready.dev/guides/iphone-duo-design-guidelines): Design rules for iPhone Duo apps aimed at designers and product managers: continuity between displays, two-column layouts on the inner display, the half-fold pose, the fold and camera regions, and what to hand engineering.

## FAQ
- Q: Does my existing iOS app work on iPhone Duo without changes? A: Usually it launches and runs. Apple lets unmodified apps run on the inner display with limited screen usage that later SDKs extend, but layouts built for a single 6-inch portrait screen often show stretched controls, clipped content, wrong safe areas around the fold, and navigation that ignores the wider size class. It works, but it does not look like a Duo app, and reviews notice.
- Q: What is an iPhone Duo readiness audit? A: We run your build in the Xcode 27.1 iPhone Duo simulator across all six poses: closed, open and half folded, each in portrait and landscape, plus side-by-side multitasking. Every screen gets screenshots and a prioritized list of layout, safe-area, ReservedRegion, orientation and multi-window issues, with concrete SwiftUI or UIKit fixes. You get the report within five business days.
- Q: Which stacks do you support? A: SwiftUI and UIKit first. React Native and Flutter apps are supported for the audit and for layout fixes at the native and framework layer.
- Q: How long does a full Duo redesign take? A: Most apps need one to three weeks. Apps with custom navigation bars, edge-to-edge canvases, or heavy hardcoded widths take longer. The audit gives you a fixed quote before any work starts.
- Q: What is FoldCheck? A: FoldCheck is an automated compatibility tester for iPhone Duo and other foldable devices. It drives your app through every fold pose and size class, captures screenshots, flags clipped content, hardcoded dimensions, overlapping system UI and missing size-class handling, and proposes code-level fixes. It is in early access; join the list to get in first.
- Q: Does this also cover iPad multitasking and other foldables? A: Yes. The same adaptive layout work makes your app behave in iPad Split View, Stage Manager and Mac Catalyst windows. FoldCheck is designed around poses and size classes rather than a single device, so it extends to future foldables.
- Q: How much does it cost? A: Audits and redesigns are fixed price and quoted within 24 hours of your email. FoldCheck early access is free for the first apps on the list.

## Full content
- [llms-full.txt](https://foldready.dev/llms-full.txt): every guide in Markdown
- [prepare-your-app-for-iphone-duo.md](https://foldready.dev/md/prepare-your-app-for-iphone-duo)
- [iphone-duo-specs-for-developers.md](https://foldready.dev/md/iphone-duo-specs-for-developers)
- [swiftui-uikit-layouts-for-iphone-duo.md](https://foldready.dev/md/swiftui-uikit-layouts-for-iphone-duo)
- [iphone-duo-testing-checklist.md](https://foldready.dev/md/iphone-duo-testing-checklist)
- [iphone-duo-app-letterboxed-fix.md](https://foldready.dev/md/iphone-duo-app-letterboxed-fix)
- [iphone-duo-app-update-cost.md](https://foldready.dev/md/iphone-duo-app-update-cost)
- [react-native-flutter-iphone-duo.md](https://foldready.dev/md/react-native-flutter-iphone-duo)
- [iphone-duo-design-guidelines.md](https://foldready.dev/md/iphone-duo-design-guidelines)