Apple software chief Craig Federighi said in an interview that he is excited to see what developers will do with the hinge mechanism in the iPhone Duo. He said an API lets developers read the angle of the hinge with an accuracy of around five degrees, and the ability to read what Apple describes as the "pose" of the device.

Apple itself uses the hinge angle in a number of ways in software, including a feature that became an instant hit: the way the outer screen defocuses into a preview of the inner one as you open the phone. He told Donald Decodes that the feature is subtle but magical. The goal was not a fancy animation you’d think about, but something you’d perceive automatically: the screen becomes translucent, a window to what’s below. Fundamental to the device is continuity between your experience when it’s closed and what you find when you open it.

Federighi says he is confident that developers will do creative and exciting things with the hinge information exposed, just as they have with other iPhone data made available to them. For most developers, Apple is focused on communicating the pose of the device: are you in book pose, on-table pose, tent pose? Developers don’t have to work with how many degrees open it is. By communicating the pose, the frameworks can react automatically and deliver a consistent experience across apps.

He added that Apple also supports agentic coding tools to enable developers to adapt existing apps almost completely automatically. You can watch the interview below.