A flashcard app for learning that lasts

Study quietly.
Remember everything.

JustFlip! is a spaced-repetition flashcard app for iPhone, iPad and Mac. Curate your decks on the desktop, review them on the go, and let an SM-2-inspired engine surface the right card at the right moment.

  • iOS · iPadOS · macOS
  • iCloud sync built in
  • Offline first
JustFlip! app screenshot on iPhone
New — generate decks with your favorite AI agent
02

One library.
Three companions.

Capture and curate on the Mac. Review on the iPhone over morning coffee. Annotate on the iPad in the margins. iCloud keeps every card, every interval and every streak in perfect sync — without ever asking you to think about it.

iPhone, iPad and Mac with synced decks
03

Let the AI write the deck.

Two ways to create decks — full rich-content cards with agentic coding tools, or simple text-only sets directly in ChatGPT.

04

A library you can swipe through.

Browse decks as a calm, editorial list — or enter a focused review and judge each card with a Tinder-style swipe. Right for good, left for again, up for easy. The flow stays in your hand.

Card list screen
Swipe-to-review screen
05

A patient algorithm.
Five states. Lasting recall.

JustFlip! runs a refined SM-2 engine across five learning states. Cards travel through unseen, learning, reviewing, relearning and graduated, each with its own interval and ease. Urgency tells you what is most worth your time today.

  1. UnseenNever studied — ready for first contact.
  2. LearningMinutes to a day. Fresh memory taking shape.
  3. ReviewingDays to weeks. The interval grows by ease.
  4. RelearningForgotten? Back to short intervals, gently.
  5. GraduatedWeeks to months. Long-term retention.
intervaln+1 = intervaln × easeFactor

Ease grows on easy, settles on good, and contracts on hard or again — never below 1.3.

06

Not just flipping cards.
A proven way to remember.

Decades of memory research — popularized in the bestselling book Make It Stick: The Science of Successful Learning — point to one conclusion: we remember by retrieving, not rereading, and by spacing practice over time. JustFlip! turns that science into a daily habit.

Memory Time

Each review lifts recall and flattens the curve of forgetting.

Retrieval practice

Recalling beats rereading

Every card asks you to pull the answer from memory before you flip — that effort is what makes it stick.

Spaced practice

Let a little forgetting work for you

Reviews return just as memory starts to fade, when each repetition does the most good — the SM-2 engine's quiet job.

Interleaving

Mix it up

Shuffling topics in one session feels harder — and builds memory that lasts far longer than studying in blocks.

Desirable difficulty

A worthwhile struggle

Judging each card Again, Hard, Good or Easy keeps reviews honestly challenging — the kind of effort that deepens learning.

“Learning is deeper and more durable when it's effortful.”

— Make It Stick: The Science of Successful Learning
07

Cards that read like essays.

Define your cards in rich Markdown — headings, lists, code blocks, inline math, images and links. JustFlip! renders them with editorial typography so a card can be a one-line cue or a small piece of scholarship.

08

Decks that speak.

Let your cards read themselves out loud while you walk, cook, or drive. JustFlip!'s home-screen widget keeps the next review one tap away — a small, golden invitation to five minutes of practice.

09

Dark by candlelight.
Light by morning.

JustFlip! respects the system. Switch from a deep, scholarly dark to a soft parchment light — the gold and slate stay true at any hour.

Dark mode
Light mode
10

Learning, for every learner.

JustFlip! is built to work with the tools people rely on — so a deck is just as usable with a screen reader, at any text size, by ear, or in your own language.

VoiceOver ready

Navigate every deck with VoiceOver — cards, controls and each learning state are clearly labeled.

Cards that speak

Text-to-speech reads your cards aloud for eyes-free, low-vision and dyslexia-friendly study.

Dynamic Type

Respects your system text size, so cards and layout scale up without ever breaking.

Clear by design

The five learning states are set apart by label and position — never color alone — with a dedicated high-contrast mode in the works.

Speaks your language

The whole app — and this very page — is localized into nine languages.

English · Deutsch · Español · Français · Italiano · Português · 日本語 · 한국어 · Čeština

Available soon on Apple platforms

Bring JustFlip! to your shelf.

One purchase. Three platforms. A lifetime of well-spaced review.

Available in English, Deutsch, Español, Français, Italiano, Português (Brasil), 日本語, 한국어 & Čeština.