iPhone Duo
app testing
checklist.
Start with the customer journeys that matter, then change the screen around them. Use the checklist and test matrix to prepare in Xcode and plan a physical-device pass.
Updated September 20, 2026 · 7 minute read
Request a real-device testTest the task.
Then change the canvas.
A screen can look correct in isolation and still lose state, hide a control, or interrupt a task when its available space changes. Apple’s iPhone Duo preparation talk calls out flexible layouts, safe areas, and Split View. The practical test is to run your important flow through those changes.
Pick a real journey first: sign in, find content, create something, or complete a transaction. Repeat it while opening, closing, rotating, or sharing the screen.
An iPhone Duo
app test matrix.
Run the same important journey through each supported state. Record the build, starting screen, expected result, and evidence so every finding can be reproduced.
| Device state | Test action | What should remain true | Useful evidence |
|---|---|---|---|
| Outer display | Complete a critical flow on the closed device. | Text, navigation, forms, and primary actions remain visible and reachable. | Screenshot and flow result |
| Inner display | Repeat the flow with the device open. | The wider layout uses space deliberately without hiding or duplicating controls. | Screenshot and flow result |
| Open mid-task | Enter data or select content, then open the device. | Input, selection, scroll position, and navigation state survive the transition. | Short screen recording |
| Close mid-task | Begin on the inner display, then close the device. | The same task continues on the outer display without a reset or blocked action. | Short screen recording |
| Rotation | Rotate during the agreed flow in each supported device state. | Content reflows, overlays stay attached, and focused controls remain usable. | Before-and-after screenshots |
| Split View | Resize the app while it shares the inner display. | Essential content and actions remain available at narrower widths. | Recording plus final screenshot |
This matrix is a practical starting point. Add cases for your app’s keyboard behavior, media, authentication, accessibility, purchases, and error recovery.
Five checks
worth running.
- 01LAYOUT
Open and closed layouts
Launch the app in each display state. Check readable text, visible navigation, and controls that remain reachable without crowding or unused space.
- 02CONTINUITY
Change state mid-task
Start a key flow on the outer display, open the device, then close it again. Look for lost input, a reset screen, or navigation that changes unexpectedly.
- 03REACHABILITY
Safe areas and system controls
Inspect buttons, forms, toolbars, and overlays near screen edges. Apple notes that iPhone Duo safe areas can be asymmetric, especially in landscape and Split View.
- 04RESIZING
Rotation and Split View
Repeat the same task after rotation and while the app shares the inner display. Check that essential content stays visible and usable as width changes.
- 05REAL DEVICE
Touch and reliability on hardware
Once the phone is available, verify gestures, tap targets, smoothness, crashes, and any behavior that only becomes clear when the device is in hand.
Technical basis: Apple Developer’s iPhone Duo resources and Prepare your app for iPhone Duo. This is a planning checklist, not a report of tests already performed.
Prepare now.
Confirm on device.
Use Apple’s tools.
Build with the iOS 27.1 SDK and preview flexible layouts in the iPhone Duo simulator in Device Hub. Apple’s current resources cover poses, safe areas, and Split View.
See Apple’s resources ↗Check real behavior.
Run the agreed flows on physical hardware, change display states during use, and capture clear evidence for anything that breaks.
Request a device test ↗Need a deeper service outline? Read the iPhone Duo compatibility testing guide or see how TestFlight testing works.
Make your test
request useful.
Tell me what a successful run looks like. The clearest requests include an app name, TestFlight link when available, the two or three flows that matter most, and any specific screen or transition you’re concerned about.
Ready for a real-device pass?
Requests are open now. Testing begins after I receive the iPhone Duo; scope and timing are confirmed before work starts.
Common questions.
Can you test my app before the iPhone Duo is available?
I can review your request and plan the scope now. Physical-device testing begins after I receive the phone.
Do I need a TestFlight link to ask?
No. You can describe the app and the flow first, then share the build when it is ready for testing.
Will you test both display states?
Yes, if they are part of the agreed test scope. The request form lets you identify the transitions and screens that matter most.
Can I request a retest after a fix?
Yes. Mention the issue you want checked again, and I’ll confirm the scope and availability.