FSRS scheduling
checkst schedules every review with FSRS. The algorithm estimates difficulty, stability and retrievability for each card and updates them after every rating with Again, Hard, Good or Easy.
Features
Everything a flashcard app needs to do. And a few things more.
checkst is a native app for iPhone and iPad. Here is what is inside, and where there are limits, those too.
Learning
Target retention instead of gut feeling
FSRS plans toward a desired retention rate: the share of cards you still remember when they come due. Higher targets mean shorter intervals and more reviews. That is the honest trade-off.
Source: FSRS4Anki Tutorial
Exam mode
Exam in two days? Enter the date, and checkst quizzes you at short intervals until then, without permanently distorting the normal intervals of your cards.
Free study
A specific deck, only new cards or only review cards, filtered by tags, with its own limit and, if you wish, independent of due dates: with dedicated study sessions you learn what you need right now.
Anki templates and cloze deletions
Basic, reversed cards, cloze, conditional fields and type-in-the-answer cards from Anki templates are displayed the way the deck intends.
Image occlusion, formulas, furigana
Image occlusion cards in Anki format, one card per hidden area. Formulas in MathJax notation are typeset, and the furigana filter sets the reading above the kanji.
Creating cards
On-device AI
checkst creates cards with Apple's Foundation Models directly on your iPhone. Apple describes the local model as private and usable offline. Requirements: your device supports Apple Intelligence, it is turned on and the model is loaded.
Or with your OpenAI key
No suitable device, or prefer a larger model? Store your own OpenAI key. Then the text goes directly from your device to OpenAI, not to checkst.
Or without any key
Without Apple Intelligence and without a key, checkst copies a ready-made prompt for you. You paste it into an AI chat of your choice, copy the answer back, and checkst turns it into card suggestions.
You decide what stays
Basic, cloze or mixed. Each suggestion first lands in a list, you select what you want, and only then is it saved.
PDF in split view
Lecture slide on the left, card editor on the right. You flip through the PDF and write the card while the slide stays open.
Text from images
Pick a picture of a book page or a blackboard from your media library. Text recognition uses Apple's Vision framework, which recognizes text on the device, including in multiple languages.
Read aloud
checkst reads cards aloud with the voices of your iPhone, with a language setting per field. Handy for vocabulary where you want to hear the pronunciation.
Anki-compatible
.apkg import
Open an Anki deck as .apkg, including directly from the Files app or the share menu, also in the newer Anki format anki21b. According to the Anki manual, a package can contain notes, note types, cards, media and optionally the study progress. If the progress is included, checkst keeps it by default; if you would rather start fresh, you reset it during import.
Source: Anki Manual: Packaged Decks
Whole collection as .colpkg
You can also open a complete Anki collection. Unlike in Anki, it does not replace anything in checkst: the decks from the .colpkg are added alongside your existing ones.
.apkg export
Your decks belong to you. Export them as .apkg and take them wherever you want.
Source: Anki Manual: Exporting
Deck gallery
Browse public decks hosted on GitHub and load them directly into the app.
Learn together
Study groups
Start a group for your course, share decks with everyone and see who is taking part. Inviting works via link or QR code.
Leaderboard
XP and streaks by week, month or all time. Motivating, as long as you don't study only for first place.
Stay on track
Streaks, XP, achievements
Every study day counts toward your streak, every card earns XP, plus achievements and daily challenges.
Freeze for bad days
If you study on five days of a week, you earn a freeze. It freezes your streak on one missed day. You can collect at most two and give one to someone in your study group once per week. Freezes cannot be purchased.
Reminders
checkst reminds you when cards are due. The notification tells you how many there are, so you know what you are getting into.
Widgets
Your due cards on the home screen. How often the widget refreshes is ultimately decided by iOS, not by us.
Source: Apple Developer: Widget timeline
Sync and account
iCloud
Your collection lives in your private iCloud database, which by default only you can see. Your review history comes along, so you continue studying on iPhone and iPad with the same state. iCloud sync is free.
Source: Apple Developer: CKContainer
checkst Pro
4.99 EUR for six months, matching a semester, as a subscription that renews automatically. It unlocks syncing via your checkst account. Sync via iCloud is included without Pro, and groups are free.
Frequently asked questions
Does the on-device AI work on every iPhone?
On-device AI requires a device with Apple Intelligence, on iPhone from the iPhone 15 Pro onward, Apple Intelligence turned on and a loaded model. On other devices you can use your own OpenAI key, copy the prompt into an AI app of your choice, or write the cards yourself.
Does checkst take over my study progress from Anki?
Yes, if it is included in the package. When exporting, Anki lets you choose whether scheduling and media are included in the package. If the study progress is in it, checkst takes it over by default. If you would rather study an external deck from the beginning, reset the progress during import.
How accurate is the text recognition?
It depends on the image. There is no universal accuracy figure for German study materials. So please check the recognized text briefly before it becomes cards.
Does checkst sync with AnkiWeb?
No. You exchange decks with Anki via .apkg. Between your own devices, checkst syncs via iCloud or your checkst account.
Is there checkst for Android?
No. checkst is built only for iPhone and iPad.
Sources
- Open Spaced Repetition: The Algorithmgithub.com
- FSRS4Anki Tutorialgithub.com
- Open Spaced Repetition: srs-benchmarkgithub.com
- Apple Developer: Foundation Modelsdeveloper.apple.com
- Apple Developer: Model availabilitydeveloper.apple.com
- Apple Developer: Recognizing Text in Imagesdeveloper.apple.com
- Apple Developer: AVSpeechSynthesizerdeveloper.apple.com
- Apple Developer: Widget timelinedeveloper.apple.com
- Apple Developer: CKContainerdeveloper.apple.com
- Anki Manual: Packaged Decksdocs.ankiweb.net
- Anki Manual: Exportingdocs.ankiweb.net