The QR Code That Stops Scanning at the Fold

UniAuth ID 1.1 for iPhone has been on the App Store since 9 October, built with the iOS 27.1 SDK: the one that gives an app the full layout for iPhone Duo rather than only dynamic resizing. The Mac app went out alongside it. Apple opened Duo submissions on 5 October, and the device ships on 23 October.

For most apps a foldable is a layout exercise. For an identity app it is not only that. Two of the changes in this release are about correctness, and before it both of them failed without an error.

A code across the fold does not scan

An Identity Pass is the thing you hold up at a door. On a half-folded phone, which is the natural way to hold it out or prop it on a counter, the pass used to draw its QR code straight across the crease. Nothing errors. The screen looks fine to the person holding it. The scanner simply does not read it, and the person at the door sees a phone that does not work.

The same is true of a code drawn under the camera cut-out on the outer display, which is always there.

The pass now asks the system where the fold and the cameras are, through ReservedRegion, which iOS 27.1 adds, and lays the code out around them:

free    = display bounds, minus every reserved region (the fold, the cameras)
panel   = the free rectangle that holds the largest square
code    = drawn in the square that panel holds

On every other iPhone the query returns no regions, the free rectangle is the whole display, and the layout is exactly what it was before. That matters: a fix for one device that moves the code on every other one is a new bug, not a fix.

A selfie under the camera is the photo a reviewer rejects

Identity verification asks for a selfie. On the inner display, the camera only covers part of the screen while it is live, which is exactly when that screen is up. A frame drawn across the cut-out puts part of your face where no pixel can show it, and that is the photo a reviewer rejects.

The selfie screen uses the same reserved regions to keep its frame, and your face, in the part of the display that can actually show them.

Two sets of controls, ninety degrees apart

The second story is a visual one. On the outer display, iPhone Duo puts the status bar and the tab bar vertically, down the right-hand edge. UniAuth ID drew its own controls (add, notifications, your account) in a horizontal row across the top. On a phone that is fine. On the outer display it left two sets of controls at ninety degrees to each other.

UniAuth ID on the iPhone Duo outer display before 1.1: the add, notifications and account buttons sit in a row across the top, while the time, Wi-Fi status and the five tabs run down the right-hand edge. — Before: the app's controls across the top, the system's down the side.

UniAuth ID on the iPhone Duo outer display in 1.1: one column down the right-hand edge holds the time and Wi-Fi status, then add, notifications and account, then the five tabs; the content keeps the full width. — After: one column. Status, then the app's actions, then the five destinations.

In 1.1 they form one unbroken column: the status bar, then the app's actions, then the five destinations. The content gets its top row back. This is Apple's own pattern; in its words, "the position of controls on the vertical axis is one of the core patterns of iPhone Duo" (Human Interface Guidelines, Designing for iPhone Duo). It is also a good illustration of the general point: on this device the system has opinions about where controls go, and an app that draws its own chrome has to hand them over.

Everything else in 1.1

Every orientation. The app was portrait-only. On a device that resizes rather than rotates, that is not a preference. It is a refusal.
The camera stays level. Neither the QR scanner nor the selfie camera set a rotation, which was correct only while "up" was a constant. Both now use AVCaptureDevice.RotationCoordinator, which follows the device.
The right display. The pass took its brightness and rendering scale from the main screen. On a phone with two displays, that is the other display's answer: it would have brightened the screen the code was not on.
A sidebar on the inner display, a tab bar on the outer one, chosen from size classes, never from a check for a particular device.
Landscape on every iPhone, not just Duo.

What we have verified, and what we have not

We checked 1.1 by screenshot in the iPhone Duo simulator, unfolded and closed. We could not drive the hinge: pose control in Xcode 27.1's Device Hub is GUI-only, so the half-folded poses have not been photographed. The fold-safe geometry is covered instead by fifteen unit tests, and has not yet been photographed folded.

We have run the simulator only, not the physical device, so this post makes no claim about how the hardware behaves, and none about performance or battery life. What it claims is what the app does: it asks the system where the fold and the cameras are and keeps the pass and the selfie frame clear of them, its controls sit in the column where the system puts its own, and on a phone with no reserved regions the pass is laid out exactly as before.

UniAuth ID is on the App Store for iPhone, iPad and Mac.