Flashcards whose answer arrives as you open the phone: stop as soon as you know it
Does RectoVerso: Flashcards work on iPhone Duo?
Yes, from launch day, and seen in simulator screenshots: open the phone and the answer arrives a little at a time with the hinge; how far you opened decides when the card returns.
- Simulator verifiedSimon Pinkas, the developer, in a submission to FoldHunt on October 22, 2026, describing the closed, opening, half-folded, open and Split View layouts. The press kit has screenshots set in Apple's iPhone Duo artwork. RectoVerso came out on the App Store on October 23, 2026, at version 1.0.2: its description has an On iPhone Duo section, and the release notes mention opening iPhone Duo to reveal a figure's labels and Stats showing its chart beside the summary on the open, upright phone.
Adapted for the fold
- Closed · Outer display
A card on the cover
Closed, a card fills the cover with its answer hidden under a sheet you slide up with your thumb. Turned sideways, the question sits on the left and the answer is pulled in on the right.
- Book · Partly folded
The answer arrives with the hinge
Opening the phone is how you answer: the inner display comes on partway, and from there the answer arrives in step with the hinge, letter by letter, term by term or line by line, whole at 150°. Stop as soon as you know it; how far you opened decides when the card comes back, and closing the phone after answering turns to the next card.
- Book · Partly folded
Two pages, or question above answer
Held partly folded like a book, the question is the left page and the answer the right, with nothing in the fold. Stood like a laptop, the question sits above the fold and the answer and its notes below.
- Open · Inner display
Open flat
Open flat, you pull the answer up, or reveal it by opening a little further. With the open phone upright, Stats shows its chart beside the summary.
- Split View · Two apps
The closed layout beside another app
In Split View, RectoVerso's half is laid out like the closed phone, and the hinge still reveals the answer once it's open past 100°.
About RectoVerso: Flashcards
RectoVerso is a flashcard app where you never rate how hard a card was. You reveal as much of the answer as you need, then say whether you knew it, and how much you revealed decides when the card comes back, scheduled by FSRS-6, the open scheduler Anki also uses. What you reveal can be letters, the terms of a formula, lines of code or part of a picture, and cards you keep revealing most of are marked fragile, with an offer to split or rewrite them. Anki decks come in with their pictures, sounds and schedule, including math, chemistry, code, furigana, Chinese tone colors and image occlusion, and go back out again. You can write your own cards, or have Apple Intelligence draft them on the phone from English web pages, PDFs and documents. It’s a one-time purchase, with no subscription, account or tracking.
On the iPhone Duo, the hinge is the reveal. Closed, a card’s question fills the cover; open the phone and the answer arrives a little at a time as the hinge opens, so you stop as soon as you know it. Half-folded, the question and answer face each other as two pages, or sit above and below the fold when the phone stands like a laptop. Close it after answering and the next card is ready. On other iPhones, you slide the answer up with your thumb instead.
Evidence reviews
What we checked, when, and what the evidence establishes. Each record preserves the support label at that check.
· Simulator screenshots reviewed
Simulator verified · iphone-duo
Checked the press kit's screenshots, flat captures with the 09:41 status ring set in Apple's iPhone Duo artwork: open, a skull diagram on the left beside the card's back, with the label Temporal revealed letter by letter, and Stats with retention and effort beside per-deck charts; closed, a Chinese card with its answer partly revealed under a pull-up sheet, and the closed phone turned sideways with Euler's formula beside its answer.
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.
Still captures from October 16, so the reveal that follows the hinge can't be seen. The tabletop picture is a render from Bitrig's 3D simulator, and the press video puts the screens on a rendered phone, so neither is counted; Split View isn't shown. No app or Xcode version is given, and no build was tested.
View reviewed evidence ↗
Watch it unfold
Related guides
Split View on iPhone Duo: two apps side by side
iPhone Duo is the first iPhone that can show two apps at once. How Split View works, what its limits are, and which apps are built to share the screen.
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 on day one, from Apple's four launch partners to indie apps whose developers have shown a real iPhone Duo layout, picked for what they do when you open the phone.
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/rectoverso/"><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: RectoVerso: Flashcards on the App Store (apps.apple.com) · RectoVerso press kit, with iPhone Duo screenshots and the press video (rectoverso.code-think.com) · RectoVerso: flashcards that unfold on iPhone Duo, on YouTube (youtube.com)
More for iPhone Duo
Facing Pages
DM Solutions and Development LLC
Bilingual stories that open like a book, the language you're learning beside your own
Simulator verified: DM Solutions and Development, the developer, in a submission to FoldHunt on October 15, 2026, saying it will be ready on launch day, with a recording of version 1.0 in the iPhone Duo simulator on YouTube. The app is on the App Store as Facing Pages: Learn Languages (version 1.0.2, first released October 19, 2026), and its description has a "MADE FOR IPHONE DUO" section.
- Closed
- Open
- Book
Lumessa
Lumessa Limited
Daily vocabulary as two pages: the word on the left, each lesson step on the right
Simulator verified: Lumessa Limited, the developer, in a submission to FoldHunt on October 22, 2026, pointing to iPhone Duo screenshots on its press page, captioned as captured in Apple's iPhone Duo simulator. The release notes for version 1.2.0 (released October 21, 2026) say that when you open the phone, Lumessa spreads across both pages, with the word on the left and each step on the right.
- Open
- Closed
Nurie: Photo Coloring Book
Haruhiko Kishi
A coloring canvas that expands on the Duo and continues on the cover
Simulator verified: Haruhiko Kishi, the developer, on the product page for the app, which shows unframed screenshots of it on the iPhone Duo's cover and open display. The App Store release notes for version 1.3.7 (released October 16, 2026) say it works on iPhone Duo, and that opened flat you can color across the whole big screen. The screenshots don't say which app version they show.
- Closed
- Open