With the new iPhone Duo, Apple is taking a little bit of a software gamble. All apps, in order to take advantage of the larger inner display of iPhone Duo, will need to be recompiled for iOS 27.0 at a minimum. To use the Duo’s unique new tab bar and other UI components, you’ll need iOS 27.1.
Of course, this means a lot of developers will have to rebuild to support the Duo. On the flip side, it also means Apple is taking a risk of many apps on iPhone Duo being stuck in black bars.