A handwriting trainer for Chinese characters with a roomier page open
Does HanziAgain work on iPhone Duo?
Yes. HanziAgain has a layout made for iPhone Duo, and FoldHunt's editor has checked it in the simulator.
- Simulator verifiedDoran Gao, in a YouTube video of simulator recordings posted on October 10, 2026 about adapting the app for the Duo (youtube.com). The app's bundle id, com.dorangao.hanziagain, carries the same name. The App Store seller is Sipeng Gao (id 6789671425). The current version is 2.0 (released October 16, 2026); its release notes don't mention the Duo, so the layout in the video may not have shipped yet.
Adapted for the fold
- Closed · Outer display
Actions on the right of the cover
Closed, the practice actions and tabs move to a rail on the right of the cover so the writing paper stays clear.
- Open · Inner display
A roomier practice page open
Open, the same practice flow gets more room; the navigation returns to the bottom of the larger page.
About HanziAgain
HanziAgain helps people who can read Chinese characters remember how to write them, by tracing or writing from memory, with stroke order and Mandarin pronunciation. A video from its developer shows it on the Duo simulator: closed, the practice actions and tabs move to a rail on the right of the cover so the writing paper stays clear; open, the same practice page gets more room and the navigation returns to the bottom. Doran Gao also turned the lessons into a reusable Codex skill for adapting other iOS apps. The Duo version isn’t in the release notes yet.
Evidence reviews
What we checked, when, and what the evidence establishes. Each record preserves the support label at that check.
· Simulator recording reviewed
Simulator verified · iphone-duo
The developer's simulator recordings show HanziAgain running closed, with the practice actions and a rail of tabs on the right edge, and open, with the same practice page and the tabs back at the bottom.
Poses shown: Closed, Open. These are observations of the evidence, not a test of every interaction.
App version: Not recorded in this evidence. Environment: iPhone Duo simulator.
Edited recordings with no app or Xcode version, and the App Store version predates the Duo. No build was tested.
View reviewed evidence ↗· Developer media reviewed
Developer claimed · iphone-duo
Watched the developer's video frame by frame: the cover with the practice actions and tabs in a rail on its right edge, and the open display with the same practice page, more room and the tabs back at the bottom, each beside an iPhone 18 Pro.
Poses shown: Closed, Open. These are observations of the evidence, not a test of every interaction.
App version: Not recorded in this evidence.
Edited simulator recordings with no app or Xcode version, and the App Store version predates the Duo. No build was tested.
View reviewed evidence ↗
Watch it unfold
On the ideas wall
All ideasHanziAgain: a side rail on the cover keeps the paper clear
by Doran Gao
Doran Gao's Chinese handwriting trainer on the Duo simulator. Closed, the practice actions and tabs move to a rail on the right of the cover so the paper stays clear. Open, the page gets more room and the tabs return to the bottom.
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.
<a href="https://foldhunt.com/apps/hanziagain/"><img src="https://foldhunt.com/badges/featured-on-foldhunt.svg" alt="Featured on FoldHunt" width="220" height="54"></a>Need to update the listing? Email the editor.
Sources: HanziAgain on the App Store (apps.apple.com) · Doran Gao on YouTube (youtube.com)
More for iPhone Duo
Netflix
Netflix, Inc.
Clips on the outer screen, cinema on the inner one, redesigned for iPhone Duo.
Launch partner: Named by Apple as an iPhone Duo launch partner.
- Closed
- Open
- Book
- Standing
Prime Video
Amazon
Amazon's streaming service: half folded, the video above and X-Ray below
Launch partner: Named by Apple in its Newsroom article of October 22, 2026, on apps optimized for iPhone Duo. The App Store release notes for version 10.154 (released October 27, 2026) don't mention the Duo.
- Book
- Open
KakaoPage
Kakao Entertainment
Comics, novels and books from Kakao, read like a book on the open Duo
Launch partner: Named by Apple in its Newsroom article of October 22, 2026, on apps optimized for iPhone Duo. The App Store release notes for version 7.34.2 (released October 22, 2026) list "Compatible with iPhone Duo".
- Open