Walks you through phone checks, with the touch test sized for the open Duo
Does Phone Checkup - Device Test work on iPhone Duo?
Yes, the developer says so: version 1.0.1 fills the open Duo display and keeps the touch-test squares a comfortable size.
- Developer claimed3810 Production, the developer, in the App Store release notes for version 1.0.1 (released October 15, 2026), which say the app is optimized for iPhone Duo, fills the large inner display when unfolded, and keeps the touch-test squares a comfortable size.
Adapted for the fold
- Open · Inner display
A grid sized for the open display
Open, the app fills the large inner display, and the squares in the touch test stay a comfortable size.
About Phone Checkup - Device Test
Phone Checkup tests a phone or tablet from top to bottom, one step at a time: screen, touch, speakers, microphone, cameras, buttons, charging and Face ID or Touch ID. A full check takes about three minutes. It also has a checklist for buying a used phone and saves the results as one image you can share.
Version 1.0.1 is optimized for iPhone Duo. Open, it fills the large inner display, and the touch test keeps its grid squares a comfortable size.
Evidence reviews
What we checked, when, and what the evidence establishes. Each record preserves the support label at that check.
· Developer statement reviewed
Developer claimed · iphone-duo
Read the App Store description and release notes, and looked at all seven phone screenshots: the check overview, function checklist, touch grid, results, buying checklist, selling guidance and speaker test. Several screens show an iPhone 18 Pro Max.
App version: 1.0.1.
The seven pictures show ordinary phone layouts, not the Duo. The larger touch grid was not shown or tested, and no build was run.
View reviewed evidence ↗
Related guides
The best iPhone Duo apps so far (October 2026)
The apps worth installing now that iPhone Duo is on sale, from the apps Apple named as launch partners to indie apps whose developers have shown a real iPhone Duo layout, picked for what they do when you open the phone.
Do your apps work on iPhone Duo? What happens before they're updated
Every iPhone app opens on iPhone Duo, but only updated ones fill the inner display. What an app looks like before its developer adapts it, how to tell which are ready, and which popular apps have said so.
Is this your app?
Add the badge to your site or press kit. It links back to this page, where fans can upvote you.
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Sources: Phone Checkup - Device Test on the App Store (apps.apple.com) · Phone Checkup - Device Test in Apple's app lookup (itunes.apple.com)
More for iPhone Duo
KeepCount
Tyler Hillsman / 1881 Digital, LLC
A board of tally counters: half-folded, counts sit above the fold and the buttons below
Simulator verified: Tyler Hillsman, the developer, in a submission to FoldHunt on October 17, 2026, with an unframed screenshot of the app in the iPhone Duo simulator in the press kit (keepcount.app). The App Store seller is 1881 Digital, LLC. The release notes for version 1.8 (released October 12, 2026) say KeepCount now adapts to the iPhone Duo's inner and outer displays, with a tabletop layout when it's partly folded.
- Book
- Closed
- Open
Calc Pro - The Best Calculator
Panoramic Software Inc.
Ten calculators and converters, with the tape of results beside the calculator when open
Simulator verified: Panoramic Software Inc., the developer, in a submission to FoldHunt on October 18, 2026, and in the App Store release notes for version 7.0.6 (released October 12, 2026), which describe the closed and open layouts. The app's page on the developer's website has pictures of both on the iPhone Duo.
- Closed
- Open
Sticky Widgets
Tyler Hillsman / 1881 Digital, LLC
Sticky notes as widgets, with a larger library and side-by-side editing on the Duo
Simulator verified: Tyler Hillsman, the developer, in the App Store release notes for version 5.4.0 (released October 13, 2026), which add iPhone Duo support with a larger library and side-by-side editing, and in a submission to FoldHunt on October 17, 2026, with an unframed screenshot of the app in the iPhone Duo simulator in the press kit (stickywidgets.app). The App Store seller is 1881 Digital, LLC; the App Store pictures show ordinary iPhones and iPads.
- Open