A comic reader whose two-page spread meets at the crease
Does Penguin Viewer work on iPhone Duo?
According to its developer, yes. FoldHunt's editor hasn't checked Penguin Viewer on iPhone Duo yet, so it's listed as a claim.
- Developer claimedThe developer, in the release notes for version 1.8.2 (released October 9, 2026), which say it now officially supports iPhone Duo and describe the open layout. There are no pictures of it on the Duo yet. The App Store seller is HAEDUN KIM (id 6780071705).
Adapted for the fold
- Open · Inner display
The spread meets at the crease
Open flat, the reader fills the inner screen, the middle of a two-page spread lines up with the crease, and the toolbar keeps off it.
About Penguin Viewer
Penguin Viewer reads your own comics, webtoons and novels (CBZ, CBR, ZIP, PDF, EPUB and more) without unpacking them, and can translate them on the device. Version 1.8.2 officially supports iPhone Duo, the release notes say: open, the reader uses the whole inner screen, the seam of a two-page spread lines up with the crease and the buttons stay off it; held half-folded like a book, the pages stay put. There are no pictures of it on the Duo yet.
Related guides
iPhone Duo poses: closed, open, book, standing and Split View
A plain-language guide to the ways you will hold iPhone Duo, what the phone itself does in each, and the apps and ideas that make the most of them. For anyone buying one, and for anyone building for it.
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?
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More for iPhone Duo
NAVER SERIES
NAVER WEBTOON
Korean webtoons and web novels, to read on the larger display of 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 26.102.0 (released October 22, 2026) don't mention the Duo.
- Open
Vertically Verse
Jihoon Suh
Bible reader in vertical text that opens into a right-bound book spread.
Simulator verified: Jihoon Suh, on the Vertically Verse iPhone Duo page (vertically.works), with captures from the Xcode 27.1 simulator. The App Store seller is Jihoon Suh.
- Closed
- Open
- Book
OperaLibre
Donovan Montoya
Audiobook player whose reader shows two facing pages on the open Duo
Simulator verified: Donovan Montoya, the developer, merged Duo support into the app's public code (github.com) and later crease fixes with Duo simulator screenshots of the reader (github.com); the changelog listed it for version 1.3.0. The App Store version, 1.3.1 (released October 19, 2026), does not mention the Duo in its release notes.
- Open
- Book