iPhone Duo testing checklist: the pose matrix every screen must pass
Updated · 5 min read · Markdown version
Testing an app for iPhone Duo means running every screen through six poses, closed, open and half folded in both portrait and landscape, plus side-by-side multitasking, and checking each for clipped content, hardcoded widths, system UI collisions, content across the fold, state loss on handoff and broken multi-window resizing.
A single screen on iPhone Duo can render in six poses, three fold states in two orientations, plus a side-by-side window state, seven configurations per screen. Manual testing that covers all of them for a 40-screen app is 280 checks per build, which is why teams skip it. This checklist makes the matrix explicit so it can be split, scripted or automated.
The pose matrix
| Pose or window state | How to get there in the simulator | Most common defect |
|---|---|---|
| Closed, portrait | Default | None; matches existing iPhone behavior |
| Closed, landscape | Rotate | Controls hidden behind the keyboard |
| Open, portrait | Open | Single column stretched across the 4.4-inch-wide inner display |
| Open, landscape | Open, then rotate | Sidebar and detail proportions wrong |
| Half folded, portrait | Fold | Content or controls straddling the crease |
| Half folded, landscape | Fold, then rotate | Video or camera view not split top and bottom |
| Window state: open, side by side | Open, then add a second app | Layout does not collapse back to compact |
What to check on every screen
- Clipped or truncated text and images.
- Elements positioned with hardcoded widths or heights.
- Custom bars overlapping the vertically laid out system navigation and toolbar buttons.
- Important content or tap targets over the fold region or the camera occlusion.
- Scroll position, form input and playback state preserved when opening or closing the device mid-task.
- Correct collapse to a compact layout when the window is resized in multitasking.
- Asymmetric safe areas respected on the inner display.
- Dynamic Type at the largest accessibility sizes on both displays.
Transitions, not just poses
Test the moves between poses as well as the poses themselves: closed to open while a sheet is presented, open to half folded during video playback, and resizing in multitasking while a text field has focus. These transitions expose state loss that static screenshots miss.
Automating the matrix
The manual matrix scales linearly with screen count and must be repeated each release. FoldCheck automates it: it drives a simulator build through every pose, captures screenshots, flags clipped content, hardcoded dimensions, system UI collisions and content across the fold, and proposes SwiftUI or UIKit fixes. It is in early access and free for the first apps on the list.