Not every flashcard app is a spaced repetition app. Plenty of study tools let you flip through cards, but only some actually schedule your reviews using the expanding interval system that makes the technique work.
This guide covers six apps that genuinely use spaced repetition — or something close to it. For each one, we cover what it does well, what it costs, and who it is built for. No filler, no affiliate links, no ranking apps we have not actually used.
What Makes an App "Spaced Repetition"
Before the list, a quick filter. A real spaced repetition app does three things:
- Tracks each card individually. It knows which cards you find easy and which ones you struggle with.
- Schedules reviews at expanding intervals. Cards you know well appear less often. Cards you miss appear sooner.
- Adapts to your performance. The schedule is not fixed — it changes based on how you rate each card.
Some apps on this list meet all three criteria. Others meet two out of three and fill the gap with other study features. We will be upfront about the difference.
1. Sticky
Platform: iOS Price: Free (premium options available) Algorithm: SM-2
Sticky is built around two ideas: AI card creation and SM-2 spaced repetition scheduling.
The standout feature is turning your own study material into flashcards without manual entry. Snap a photo of lecture notes, a textbook page, or a whiteboard, and the AI generates question-answer pairs in seconds. You can also paste text with Note to Card or speak your notes using Voice to Card. Once the cards exist, the SM-2 algorithm schedules every review individually based on your Easy, Medium, and Hard ratings.
Reviews from all your decks are pulled into a single daily session, so you never have to decide which deck to open. The app tracks your performance per card, adjusts intervals automatically, and shows you exactly how many cards are due each day.
Best for: Students who want to study their own notes without spending hours on card creation. If you have lecture slides, handwritten notes, or textbook chapters and want them turned into a spaced repetition deck fast, this is the fastest path from material to studying.
Limitations: iOS only. No desktop app. Less customisation than power-user tools like Anki.
2. Anki
Platform: Desktop (Windows, Mac, Linux), iOS ($24.99), Android (free), Web Price: Free on desktop and Android; $24.99 one-time on iOS Algorithm: SM-2 default, FSRS optional
Anki is the most established spaced repetition tool in the world. Open-source, deeply customisable, and backed by nearly two decades of community development. Over 86% of American medical students report using it.
The core experience is creating or downloading flashcard decks and reviewing them on a schedule. Anki supports basic cards, cloze deletions, image occlusion, and fully custom HTML/CSS templates. Close to 2,000 community-built add-ons extend functionality in every direction: review heatmaps, text-to-speech, collaborative editing, and more.
The newer FSRS algorithm uses machine learning to personalise intervals based on your individual memory patterns, reducing daily review counts by an estimated 20 to 30 percent compared to default SM-2.
Best for: Power users who want total control. Medical students with access to community decks like AnKing. Anyone who studies primarily on desktop and values open-source software. Full Sticky vs Anki comparison.
Limitations: Steep learning curve. The interface is functional but dated. Card creation is entirely manual unless you install third-party add-ons. New users often spend weeks learning the tool before feeling productive.
3. Quizlet
Platform: Web, iOS, Android Price: Free tier; Quizlet Plus at $35.99/year Algorithm: Adaptive (not traditional SRS)
Quizlet is the most widely used study platform in the world, with hundreds of millions of flashcard sets across every subject. Its strength is breadth: multiple study modes (Learn, Test, Match, Flashcards), a massive library of user-generated content, and availability on every platform.
Quizlet's Learn mode uses an adaptive algorithm that adjusts question difficulty based on your responses and a target test date. It incorporates spacing principles but is designed more for short-term exam preparation than long-term retention. There is no user-visible interval system or ease factor.
The Magic Notes feature generates flashcards from uploaded documents, notes, and photos, though full access requires a Plus subscription.
Best for: Students who want pre-made study sets for common courses and exams. Group study with shared sets. Short-term exam prep where the goal is passing next week's test rather than retaining material for months. Full Sticky vs Quizlet comparison.
Limitations: Not a true spaced repetition system — the adaptive algorithm is closer to smart quizzing than expanding-interval scheduling. Key features locked behind the $35.99/year subscription. The free tier includes ads.
4. Noji (formerly AnkiPro)
Platform: iOS, Android, Web Price: Free (50 cards/day limit); Premium at $4.99/month or $17.99/year; Lifetime at $74.99 Algorithm: SM-2
Noji launched as a modern, polished alternative to Anki. It uses the SM-2 algorithm, offers image occlusion, and has a library of over 50,000 pre-made decks. The interface is clean and approachable — a clear step up from Anki's utilitarian design.
Premium users can adjust spaced repetition presets for different study goals (language learning, medical study, general), and the app includes AI card generation from prompts and PDF imports.
Best for: Students who want an Anki-like experience with a modern interface and cross-platform sync. Language learners who want pre-made decks with audio pronunciation. Full Sticky vs Noji comparison.
Limitations: The free tier caps you at 50 cards per day, which is too low for serious use. Key features including AI generation, image occlusion, and custom SRS settings are locked behind Premium. The name change from AnkiPro caused community confusion.
5. Memrise
Platform: Web, iOS, Android Price: Free tier; Pro at $8.49/month or $59.99/year Algorithm: Proprietary adaptive
Memrise started as a vocabulary learning platform and has evolved into a broader language learning app. It uses a spaced repetition system for vocabulary review, combined with video clips of native speakers, grammar exercises, and pronunciation practice.
The adaptive algorithm schedules word reviews based on your performance, and the app distinguishes between "learning" and "review" phases. Memrise is strongest for language learners who want an immersive experience rather than raw flashcard drilling.
Best for: Language learners specifically. The combination of spaced repetition, native speaker video, and contextual learning makes it more engaging than pure flashcard apps for vocabulary acquisition.
Limitations: Heavily focused on language learning — not useful for medical students, exam prep, or general knowledge. The free tier is very limited. No support for creating your own custom cards in the way flashcard apps allow. The spaced repetition is a feature within the app, not the core product.
6. Mochi
Platform: Desktop (Mac, Windows, Linux), Web Price: Free (100 cards); Pro at $4.99/month or $49.99/year Algorithm: SM-2 variant
Mochi is a desktop-first app that combines flashcard review with note-taking. You write notes in Markdown, then embed cloze deletions or Q&A cards directly within your notes. When it is time to review, Mochi pulls the cards out and presents them on an SM-2 schedule.
The integration between notes and cards is Mochi's defining feature. Instead of creating notes and flashcards separately, you do both at once. This appeals to learners who want a single tool for capturing and retaining information.
Best for: Note-takers who want flashcards embedded in their writing workflow. Desktop-first studiers. Developers and technical learners who already think in Markdown.
Limitations: The free tier caps at 100 cards, which is tight. No mobile-native app (the web app works on mobile but is not optimised for it). Smaller community and fewer pre-made resources than Anki or Quizlet. No AI card generation.
Quick Comparison
| Feature | Sticky | Anki | Quizlet | Noji | Memrise | Mochi |
|---|---|---|---|---|---|---|
| True SRS algorithm | Yes (SM-2) | Yes (SM-2/FSRS) | Partial | Yes (SM-2) | Partial | Yes (SM-2) |
| AI card creation | Yes (built in) | No (add-ons only) | Yes (paid) | Yes (paid) | No | No |
| Pre-made decks | Curated | Massive community | Massive community | 50,000+ | Language only | Small community |
| Free tier | Full features | Free (desktop/Android) | Limited | 50 cards/day | Limited | 100 cards |
| Platforms | iOS | All | All | All | All | Desktop + Web |
| Card from photo | Yes | No | Yes (paid) | No | No | No |
| Offline access | No | Yes | Paid only | Paid only | Paid only | Yes |
How to Pick the Right App
Skip the feature comparison grids and ask yourself three questions:
1. What are you studying?
Language learning? Memrise and Noji have dedicated features for that. See our spaced repetition for language learning guide. Medical school? Anki's community decks are unmatched. Preparing for exams? Check our week-by-week exam study plan. General coursework from your own notes? Sticky's AI card creation gets you studying fastest.
2. Where do you study?
Desktop-first? Anki or Mochi. Mobile-first? Sticky or Noji. Need every platform? Quizlet or Anki cover the most ground.
3. How much setup are you willing to do?
Want to configure everything? Anki. Want zero setup? Sticky. Somewhere in between? Noji or Mochi.
Any of these apps will produce better results than not using spaced repetition at all. The science behind spaced repetition is strong regardless of which tool delivers it. The best app is the one you will actually use every day for months. Pick based on that, not feature lists.
Our Recommendation
We built Sticky, so take this with appropriate skepticism. But here is why we think the approach matters:
The biggest barrier to spaced repetition is not the algorithm — every app on this list handles that well enough. The barrier is the setup. Creating hundreds of flashcards by hand is tedious. Learning to configure Anki takes weeks. Subscription costs add up.
Sticky removes the setup cost. Photo your notes, get cards, start reviewing. The SM-2 algorithm handles scheduling. No configuration, no subscription required for core features, no hours lost to card creation.
If that trade-off appeals to you, download Sticky and try it with your next set of notes. If you prefer more control, Anki is excellent. If you want pre-made content, Quizlet has the biggest library. There is no wrong choice — only the one that gets you reviewing consistently.
