Apple's iPhone Duo goes on sale on Friday 23 October. 6pm, our daily money app, already lays itself out for each way you can hold it. We built it in mid-October on the iPhone Duo simulator in Xcode 27.1, and it ships in 6pm 2.0.0 on the App Store on 6 November.

This post covers what the iOS 27.1 SDK gives you, how we got it into React Native, and the one design question that took the most thought: what should folding a phone shut mean in an app you close once a day?

Every snippet is from the open-source repo ( github.com/at6pm/6pm , Apache 2.0).

What the platform gives you

Three things in the iOS 27.1 SDK matter:

UIHingeInteraction : added to a view, it reports UIHinge updates with a status (closed, partially open, fully open) and an angle in radians.

UIView.reservedRegions(kind:) : .division is the fold across the inner screen, and .occlusion is the vertical island on the outer screen.…