Designed for iPhone Duo. At home on every iPhone.
A flashcard has two sides. So does iPhone Duo. The question waits on the closed phone. Open it, and the answer is on the other half. On any other iPhone, the same card flips with a tap. Study is free, and always will be.
The fold is the flip
Every posture of the phone is a way to study. None of them is required. Fold, tap, drag or press the space bar: it is one card, one schedule, one app.
Study on the outer display with the question in front of you. When you are ready, open the phone. The question stays on the left page, the answer lands on the right, and Missed and Got it sit under your thumbs. Rate it, close the phone, and the next question is waiting.
Nothing is graded for you. Close the phone on an unrated card and it is still there, revealed, when you look again.
Lay the phone flat between you and a friend. Your half shows the question, facing you. Their half shows the answer, facing them, with Hint, Missed and Got it. They quiz you the way people always have, and your schedule learns from every answer. No account for the friend, nothing copied to anyone.
On a single-screen iPhone, hand the phone over: the answer sits under a cover only your friend lifts.
Prop the phone half open on a desk. The question is on the raised half at reading distance, large and calm. The answer, the grading buttons and the explanation sit on the half under your hands, so nothing you need to touch is ever up where you are looking.
Cards from what you already have
Photograph a page or drop in a deck and the cards come back with their page references, ready to edit. Soon they will appear one at a time as they are made, each one pointing back to the sentence it came from, so you can keep the good ones, skip the rest and start studying before the import has finished. streaming at launch
Point the camera at a page of notes or a textbook. Text is read on your phone. Short passages will become cards on your phone too. on-device AI at launch
A chapter or a lecture deck becomes cards with page references, so you can always go back to the source. Pro
Anki packages import with their review history, media and sub-decks, so years of progress carry over and the schedule picks up where it left off.
Cloud results can be wrong; the cards stay editable and the source stays one tap away. Every AI result will be labelled On-device or Cloud, so you always know where it ran. labels at launch
Spaced repetition, plainly
Bifold schedules every card with FSRS-6, the open-source algorithm that modern Anki uses, and asks you one honest question: did you get it? Missed or Got it. Hard and Easy are a swipe away if you want them.
Numbers you can trust
Retention, the week ahead, and sixteen weeks of reviews, in ink on paper. When there is no data yet, the chart is replaced by a sentence that says what to do, never by a row of zeros.
Free to study. Forever.
No timers, no lockouts, no ads, and no paywall between you and a review. Bifold Pro adds cloud AI for PDFs, slides and long text, deeper explanations, and advanced stats. Prices are drafts until launch.
Free
Bifold Pro
Built for everyone
Start to finish by VoiceOver, with a rotor for the card side. Card text never truncates at the largest accessibility sizes; it scrolls. Reduce Motion swaps every animation for a crossfade. Buttons carry labels and glyphs, never colour alone.
No tracking and no third-party analytics. Your cards sync through your own iCloud. Cloud AI sends only the material you choose, and keeps nothing after the request.
Bifold is in development for iPhone Duo and every iPhone running iOS 17 or later. A student TestFlight comes first. To hear when either is ready, write to us.