Questions and answers

A flashcard app using the FSRS algorithm. It shows you each card exactly when you'd otherwise slowly forget it – not sooner, not later. So knowledge sticks without wasting time on what you've long known.

You see the front of a card, tap it to see the back, and then swipe: right if you knew it, left if you did not. The app schedules the next due date in the background.

That is everything you need to operate. With a keyboard on iPad the same works via the space bar and the arrow keys, and on Apple Watch via tap and swipe.

For anyone who wants to retain something for good: vocabulary, exam material, professional knowledge, facts. No prior knowledge needed – create cards or import them and get going.

No. Qardbox works fully offline and without signing in. iCloud sync is optional and can be turned off any time.

Your hit rate in the current session — nothing more.

Five stars mean at least 90% correct answers, four 75%, three 55%, two 35%, and one anything below. Only cards from this session count.

Don't overrate a high score early in the session: with few cards, a strong start can show four or five stars that settle quite differently over more cards. The value becomes more reliable the longer you learn.

A deliberate decision.

Multiple choice replaces active recall with recognition: you pick from given answers instead of retrieving the answer from memory yourself. It sounds similar but is fundamentally different — recognizing is much easier than recalling and leaves less behind. Anyone who practices with multiple-choice cards ends up underestimating how much they're actually missing.

Images tempt you into a form of procrastination all their own: whoever spends more time designing a card than learning has built themselves a way to put things off. What can't be captured in a clear sentence should usually become two cards — not one illustrated one.

Two levels, no more: swiping right means “known”, swiping left means “not known”. Tapping flips the card.

You can reach those same two levels in other ways: as named actions in VoiceOver, with a keyboard via the arrow keys, and on Apple Watch by swiping. What changes is the route, never the number of levels.

Because the most honest self-assessment is the simplest: did you know it or not? Fine grades like “hard” or “easy” sound more precise but are often guessed. FSRS handles the clear yes/no answer very well.

Never in the sense of “that's it for today” – you can keep learning any time. Qardbox doesn't tell you to stop. The daily goal is a motivation marker, not a cap.

Then you still won't run out of cards. Qardbox next shows the cards most nearly due again or the ones you haven't seen the longest. There's always something to practice.

A small finish line for the day — the number of cards you set out to do. By default Qardbox sets it automatically: derived from your recent active learning days (median, so it's robust against individual exceptional days). In Settings under "Learn" you can switch to a fixed value. Either way, the goal neither steers the FSRS algorithm nor limits you.

From your own learning history.

Qardbox takes the median of your daily card count over the last 30 active learning days, not the average, so one exceptional day doesn't permanently push the goal up. Regularity and retention rate also factor in: someone who learns very irregularly or has been forgetting a lot recently gets a lower goal, not a higher one.

Floor: 5 cards/day, so the streak doesn't become a burden. Ceiling: 120. Switch to a fixed value anytime in Settings under “Learning”.

Background: Research shows that around 85 % success rate is optimal for learning — just challenging enough, not frustrating. Qardbox would rather lower the goal than raise it to keep it achievable.

Because the two numbers come from different places and know nothing about each other.

“Due” is what FSRS has scheduled for today: cards whose review date has arrived. It follows from your learning history; you cannot set it.

The daily goal is your number: how many cards you intend to do. The algorithm does not know about it, and it feeds into no scheduling.

In a session the due cards come first. Qardbox then tops up with new ones, as many as “New cards per day” allows. That is how 20 due cards turn into the 40 of your goal on most days.

The other way round, the goal never slows you down: if 60 cards are due, you can learn all 60. It is a finish line, not a ceiling.

And if something is still left over at the end, then there simply are no more cards to do that day. That is not a fault but the whole point: Qardbox will not make you review what is already sticking. Extra practice is still open to you, but it deliberately counts towards neither the daily goal nor the ring, because it does not change your memory values.

Because you are finished, and that is the whole point.

Qardbox shows you a card when you would otherwise slowly forget it. Once you have done everything that was due today, there is nothing left to put in front of you. Showing you the same cards again would do nothing for your memory and would only eat the time you just saved.

Instead of an empty screen, Qardbox then offers extra practice. There you see cards whose date still lies ahead. They deliberately do NOT count as reviews: your rating changes neither the next date nor your memory values, and it counts towards neither the daily goal nor the ring. Otherwise the very calculation that saves you work would be distorted by the practicing itself.

There is one exception, and it is in your favour: extra practice does count towards rescuing your streak. Otherwise, on a day with no due cards, you could not get the five correct answers together at all and would lose your streak without having missed anything.

And a day on which nothing was due does not break your streak in the first place. It does not count as a study day either, because you did not study, but it does not stand in your way.

It shows three days at once: the day before yesterday, yesterday, and today, clockwise. The ring is open at the bottom, each day is a segment of its own, and how long a segment is depends on how many cards you learned that day.

The number in the middle is where you stand today. It is allowed to be 0 and glosses over nothing: even on a day when you have not done anything yet, the ring is not empty, because the two previous days stand beside it.

Today’s segment fills up while you learn. At its end sits a dot for the daily goal: dashed while the goal is still open, filled with a checkmark once you have reached it. Learn beyond that and a further, quietly pulsing arc joins it.

The colors are brightness steps of your accent color, stronger the closer to today. A previous day on which you studied but missed the goal has a dashed outline. A day on which you did not study at all is gray and torn open and carries no number.

You can reach every meaning without color: small knobs sit at the segment boundaries. Tap one and it says in words which day is meant and what happened on it. VoiceOver reads out the same.

Use it to mark cards you want to see more often. A bookmarked card is drawn slightly ahead when due dates are similar — so it comes up more often. Its FSRS values stay untouched; the science stays clean.

A number of ratings at which Qardbox fine-tunes your study plan. The first is 512, then 1024, 2048 and so on.

The gaps grow on purpose: the more data has already gone in, the less a single session changes it.

Ratings with a real gap of at least one day. If you draw the same card several times on one day, only one of them counts.

The reason is simple: what you still know ten minutes later says little about what sticks in two weeks. For planning, the gap across days is what counts.

The number of distinct cards the ratings come from. A thousand ratings across ten cards say less about your memory than a thousand across three hundred.

Once enough experience has accumulated. The first milestone is 512 ratings spaced at least a day apart, then 1024, 2048 and so on.

Qardbox then works out on your device whether your own learning values fit better than the tested defaults, and adopts them only if they prove better. Otherwise everything stays as it was. Every run appears in the history with its reason and time.

Settings, Learn, “Personalized study plan”, then “History”. Each entry says why a run happened or did not, and how many ratings, interday outcomes and unique cards were behind it.

Because your memory firms up most when you review just before forgetting. Cramming it all in one evening feels productive but is often gone the next day. Distributed learning lasts longer – that's the core of Qardbox.

A little every day beats a lot once a week. Ten to twenty minutes is enough for most. Regularity matters more than volume – that's what the streak is for.

Whenever it reliably fits your day – morning coffee, a break, evening on the couch. A firm anchor in your routine beats any “ideal time”. The automatic reminders learn your rhythm too.

No, quite the opposite. Recalling before you're sure firms up knowledge more strongly – even when you slip up. A little effort in retrieval is intended, not a sign of failure.

One card, one idea. A short, clear question on the front, a concise answer on the back. Avoid “lists to recite” – break them into individual cards. Your own wording sticks better than copied sentences.

The break hint is not a push or a notification — it appears as a brief in-app hint right in the learning view. It shows up once you've actively rated cards for at least 25 minutes straight. A longer pause in your learning flow resets the timer.

The reason is the attention curve: concentration noticeably drops after about 25 minutes of continuous work — the Pomodoro method follows the same principle. It stays a suggestion: keep learning or take a break, exactly as you like. Turn it off in Settings under "Learn."

On well-established memory research: the spacing effect (distributed practice), the testing effect (retrieval instead of rereading) and "desirable difficulties." Scheduling is handled by FSRS, an open, data-driven spaced-repetition algorithm. More on this — with clickable sources — under "Learning with Qardbox."

The “Free Spaced Repetition Scheduler” – the algorithm behind Qardbox. It estimates for each card when you'll likely forget it and schedules the review just before. So you review exactly when it helps most.

The share of your answers that were correct (“known”), averaged over seven-day windows. Around 90 % is the algorithm's target: high enough that you retain almost everything, low enough that you don't review unnecessarily often.

A card is due when its scheduled review date is reached – the moment FSRS wants to show it to you again. Due cards come first.

When it is so stable that the next review date is far in the future (about a month or more) and you have answered it correctly multiple times. Mastered doesn’t mean “never again” – just “deeply ingrained”.

Every answered card counts as one review. The statistics show how many there were per day, which is the same as “learned cards”.

Cards you've never studied — they're waiting for their first review and don't have a scheduled date yet. As soon as you answer one for the first time, FSRS adds it to its schedule.

FSRS tracks two values per card that you never set directly:

Stability: the estimated time until you forget the card. A new card has a stability of a few days. The more often you answer it correctly, the longer it holds. If you forget it, it drops sharply.

Difficulty: how easy this card is for you personally. Someone who keeps getting a card wrong has it rated as difficult for them, regardless of the topic. Qardbox adjusts both values automatically after every answer.

The number of consecutive days on which you've learned at least once. It's shown at the top with the flame icon. The streak measures sticking with it, not volume.

It makes consistency visible. That helps because regular learning rarely happens by itself in everyday life — it needs to become a habit. A growing streak makes sticking with it a little more concrete than an abstract intention.

Important: Qardbox only protects a single missed day, not two in a row. Behind this is a rule of thumb from habit research: missing once barely matters. Missing twice in a row breaks the pattern. Rescuing that one missed day is always worth it.

From seven days on, Qardbox bridges a single missed day. You then have until the day after next to save it with five cards you knew.

What counts is what you knew: cards you rate “Again” don’t bring you closer to the five. Free practice doesn’t count at all, because it deliberately leaves your learning plan untouched. So at a hit rate around one half, expect ten cards rather than five.

Nothing gets inflated: the missed day itself doesn’t count.

Yes, the weekly pause. Turn it on in Settings under “Learn” → “Weekly pause”. For one week the streak won't break, even if you don't learn.

Again and again – but not back to back. After one pause ends, the next becomes available only once you've learned at least once in between. That keeps it from chaining into a permanent pause.

Yes, in Settings under “Learn” → “Reset streak”. That only sets the counter to zero – your cards and learning history are kept in full.

There are four, and you pick exactly one in Settings under “Reminders”.

Never: Qardbox never gets in touch. You alone decide when to study.

Minimal: at most one message in the evening, and only on days when you have not studied yet and your streak would otherwise end.

Smart: Qardbox works out good moments from when you have studied so far, per weekday too, and watches which reminders actually lead to a round of cards. If you stop responding for a while, it quietens down by itself. Never more than three messages a day.

Helpful (default): like Smart, but some messages also tell you something about your learning. Same number of messages, more substance. A fresh install starts here, because it costs you nothing and the observations arrive on their own.

You can switch at any time.

The number of messages is the same, the content is not. Smart gives you a nudge: “Time for a few cards?” Helpful goes further and tells you something about your learning that you cannot see yourself, such as the time of day when you retain the most, or that you have got faster.

Observations like that need enough data first. In the early weeks Helpful therefore behaves like Smart. That is deliberate: better no observation than an invented one.

At most three, usually fewer. Something only comes when your daily goal is still open – otherwise, silence. Spam is explicitly not the aim.

Because Qardbox finds the right time itself, from when you have studied so far and even per weekday. On top of that, a reminder should stay a small surprise, with changing messages.

You still decide how much arrives, just through the level rather than the clock. If you want quiet, choose “Never”; if you only want a nudge about your streak, choose “Minimal”.

If you have not studied today and your streak would otherwise be at risk, Qardbox gets in touch at 9 pm so it does not lapse. That applies from your first day of studying; at a streak of zero there is nothing to save.

There is no separate switch for it any more: every level except “Never” protects your streak. On “Minimal” it is the only message you get at all.

No. During an active weekly break you rest, and no learning reminders arrive. On the first day afterwards a short, motivating message welcomes you back.

Cards in that subject get a speaker button. It reads the ANSWER SIDE of the card in the language you chose for the subject.

The answer field is always what gets spoken, even when you are learning in the reverse direction and the answer is on the front. That is deliberate: you decide once which field holds the foreign language, and then you no longer have to think about it.

Reading aloud also stays on your device: iOS generates the speech itself, and the card text is not sent anywhere for it.

Cards tab, tap the subject, then edit. Right below the name is the “Foreign language” switch. Turn it on and the row “The answer is in” appears underneath, with a list of the languages your device can speak.

When you create a new subject, the switch sits in the same place.

That is the “Read foreign languages aloud” setting. You will find it in two places: in the Learn tab behind the filter symbol, and under Settings, Learning. Both change the same value.

“Never”: no speaker buttons appear. “On request”: the buttons are there, but nothing is spoken until you tap. This is the default. “When flipping”: the answer is spoken as soon as you turn the card to the answer side. Turning back to the question stays silent. No buttons appear here; you do not need them.

Only with “On request”: After the first playback a second button with a tortoise appears next to the speaker. It says the same thing again, only slower.

Because no voice for it is installed on your device. Qardbox only lists languages that can actually speak.

You load voices in iOS Settings: Accessibility, Spoken Content, Voices. That is also where you find better versions of the languages you already have. The preinstalled ones are small compact voices and sound a little tinny; the larger downloads sound noticeably more natural. As soon as a voice is loaded, the language appears in Qardbox by itself.

Control Center is the set of switches you see when you swipe down from the top right corner of the screen. That is where the torch, aeroplane mode, music and anything else you add live.

Here is how to add Qardbox: open Control Center, tap the plus at the top left, then tap “Add a Control”. A long list appears. Scroll to Qardbox or type the name into the search field at the very top. Tap the entry you want, then tap anywhere on the background to finish. To move the switches around, press and hold one and drag it.

Three of them.

“Start session” begins a study round straight away, in the study direction you set in the app. It is the shortest way from a locked screen to your first card.

“New card” opens Qardbox and brings up the sheet for a new card right away.

“Qardbox” simply opens the app in the study area.

A widget is the small tile that shows you something without you opening the app.

Press and hold an empty spot on the Home Screen until the icons wobble. Tap the plus at the top left. Find Qardbox in the list or through the search field. Swipe sideways to look through the sizes and variants, then tap “Add Widget”.

Qardbox offers one large widget with study time, focus card and weekly goal, plus two small ones: “Cards studied” shows the last seven days, “Success ring” shows your daily goal as a ring. The same values are available in small form for the Lock Screen.

Yes, for the large one. Press and hold it and choose “Edit Widget”. You can pick between two color variants there.

The two small widgets have nothing to set. If you would rather have a different size, remove the widget and add the one you want.

Shortcuts are small jobs your iPhone carries out for you. Qardbox registers several of them with the system, so there is nothing for you to set up.

Try saying: “Start a Qardbox session”, “How many cards are due in Qardbox”, “My Qardbox streak”, “New card in Qardbox” or “Install a deck in Qardbox”.

If you would rather tap than talk: the Shortcuts app comes with every iPhone. Under “App Shortcuts” you will find every Qardbox job, and you can combine them into your own routines.

Yes, through the Shortcuts app. Open it, tap the plus, search for Qardbox and choose “Start session”. The shortcut then shows a “Subject” field. Tap it and you get a list of your subjects with their symbol and the number of cards due. Pick one and give the shortcut a name at the top, for example “Study biology”. You can then say that name to Siri.

The same works with “Check due cards”: with a subject chosen, Qardbox tells you the number for that subject alone.

If you later delete a subject a shortcut points to, Qardbox tells you so when it runs. The shortcut stays, you simply pick another subject.

The Action Button is the extra button on the left edge above the volume buttons. It exists from the iPhone 15 Pro onwards; older devices and the non-Pro models do not have it.

Two steps are needed, and the first one happens outside Qardbox.

First: open iOS Settings, tap “Action Button”, swipe to “Shortcut” and tap the field below it. Several Qardbox entries are listed there. Pick the one called “Action Button”. If you pick a different one by mistake, the button does that job instead of the one you set here.

Second: open Qardbox, go to Settings, Study, and switch on “Use the Action Button”. Below that you choose what a press should do during a study round: flip the card, mark it as saved, rate it as known or rate it as not known.

If you press the button while no round is running, Qardbox starts one.

In the Cards area, pull the list down a little and the search field appears. What you type searches questions, answers, notes and subject names all at once.

As you type, Qardbox suggests matching subjects and categories. Tap a suggestion and it becomes a filter that stays in the search field as a small chip, so you can always see what is being filtered. To lift it, tap the chip and delete it.

For the fuller picture, use the filter symbol in the toolbar. It lists every subject, every category and your saved cards to tick.

This is built in, but honestly still untested: we had no second device to try it on. What is built: if a round is running on your iPhone, a nearby iPad offers to take it over, with the same subject, the same card and the same progress. The same goes for a card you are editing.

One thing matters here: it only works if you have iCloud sync switched on. Qardbox passes on identifiers only, never card content. Without sync the other device does not know your cards, and then simply nothing happens.

You only see the question. A tap reveals the answer. Swiping right means “known”, swiping left “not known” — the same two levels as everywhere else.

A checkmark or a cross appears briefly. You do not have to wait for it: the next card is there straight away and can be swiped straight away.

Swiping down leaves the round.

With VoiceOver the sideways swipes do not work, because a horizontal swipe belongs to VoiceOver itself there. Instead the card carries three named actions: “Flip”, “Known” and “Not known”.

Three ways: with the Digital Crown, by swiping up with your finger, or with the double tap of thumb and index finger.

Swiping sideways stays the rating. watchOS decides which direction you meant — you do not have to watch out for whether you are in the middle of the text.

Yes, the last one. There is an arrow for it at the top right; it only becomes active once there is something to take back. It goes one step, no further, and only while the round is open.

The undo counts everywhere: streak, daily goal and statistics are back to where they were, on iPhone too.

⌘N adds a card, ⇧⌘N a subject. ⌘L starts a round, ⌘O opens the import, ⌘E the export, ⌘F the search field. ⌘1 through ⌘4 jump between Study, Cards, Statistics and Settings.

You do not have to memorise any of it: hold the Command key for a moment and iPadOS shows the full list.

iPhone has no menu bar. The shortcuts still work there as soon as a keyboard is connected.

Yes. The space bar flips the card — pressing it again shows the question, exactly like a second tap. Right arrow rates as “known”, left arrow as “not known”. Escape ends the round.

The keyboard has no extra levels either. Qardbox rates with the same two everywhere, whether you swipe, tap or press a key.

Yes, that is what it is built for. In the “New card” sheet, Tab moves from the question to the answer, on to the categories, the notes, the field for a new subject and finally to the two save buttons. Shift-Tab walks the same path backwards.

⌘Return saves and immediately starts the next card. Subject and categories stay filled in, everything else is cleared, and the cursor is back in the question. ⇧⌘Return saves and closes the sheet.

A whole series can be entered this way without touching the screen or the trackpad.

Through your private iCloud (CloudKit). Subjects, cards, and study progress sync automatically between your Apple devices signed in to the same iCloud account.

Sync is off by default. You enable it once under Settings → Study → iCloud Sync. After that Qardbox transfers changes in the background; changes made offline are caught up as soon as there is a connection.

Important: Qardbox never deletes anything via sync. What was removed on one device stays on the other until you delete it there too.

On the data: your data sits exclusively in a private iCloud database bound to your Apple ID. The developer has no access. The contents of your cards — question, solution, categories, note, and the subject name — are set up as encrypted fields. If you switch on Advanced Data Protection under Apple Account → iCloud, Apple cannot read them either. Ratings and study timestamps stay unencrypted; from those you can tell that you studied, not what.

Yes, in Settings under “Study” → “iCloud sync” with a switch. After that everything stays on this device and never leaves it. The change takes effect immediately.

Yes. Two columns are enough: question and solution. Category, note, and subject are optional extras.

Qardbox recognizes semicolons, tabs, and commas as separators, and it works out the column names itself, in German as well as English. Files with no header row at all work too; the first column then counts as the question and the second as the solution.

Qardbox has no partnership with any other app; detection is based solely on file format and column contents. Before importing, you see how many cards are new and how many were already there.

Under Settings → “Privacy” → “Save data copy” you create a complete copy. “Restore from data copy” plays it back; Qardbox backs up the current state first.

Settings → "Learn" → "Reset" removes learning states and reviews; the cards themselves remain. You delete individual subjects and cards directly in the Cards tab.

None. No analytics, no tracking, no advertising identifiers, no server of our own. Your data lives only on your device and – if you want – in your private iCloud. Details are in the privacy board under “Info”.

Privacy and quality.

A built-in AI would send text (your study material, notes, topics) to an external provider. Qardbox sends no data to servers, and it should stay that way.

There is a second, practical reason: AI-generated cards are often too long, too vague or factually unreliable, especially on specialized topics. A good card holds a single precise idea. Formulating it means you have understood the material, and that is not a bad way to prepare for learning.

A tool for quick bulk import.

In the import area you'll find a technical prompt you can paste into an AI of your choice. Add your topic, and the AI returns a ready-made CSV file in Qardbox format that you can import directly.

Qardbox itself sends nothing to an AI. Which service you use — and what happens to your data there — is up to you.

iOS keeps a record. In iOS Settings under “Privacy & Security”, switch on App Privacy Report. After a few days it shows, for every app, what data it uses and which addresses it contacted.

Qardbox has no server of its own. What appears there are Apple services.

That is Apple's iCloud. The entry only appears if you switched sync on; Qardbox then keeps your cards in your private iCloud database so they match across your devices.

Without sync, everything stays on the device. The address belongs to Apple, and nobody but you can reach that database.

Also Apple. The address belongs to the App Store, and iOS contacts it on the app's behalf, for example to check whether a review prompt may be shown.

No study data goes with it. Neither cards nor statistics leave your device for this.

Because nothing happened. The report records only what actually takes place. If you leave sync off, there is nothing to see for Qardbox.

VoiceOver, Voice Control, Switch Control, large text up to the highest size, dark appearance, increased contrast, reduced motion and differentiation without color.

No learning step depends on a swipe alone. On iPhone and iPad there is always a button or a key alongside it; on Apple Watch, where there is no room for buttons, named VoiceOver actions carry the same job.

Anything that affects the whole device: VoiceOver, Switch Control, Voice Control, Assistive Access, Invert Colors.

Qardbox detects these states and follows them, but cannot switch them on for you. That is deliberate: an app should not flip a system setting on your behalf.

Settings, Accessibility. Six areas, and every row says who provides it: Qardbox always, iOS right now, or a switch there.

Every Qardbox switch is off by default. With no accessibility feature active and no switch set, the app looks exactly as it always did.

Because there is no interface for it, and for good reason. Accessibility features apply to the whole device; a single app must not toggle them.

Where something is only possible in iOS, Qardbox shows an info symbol and says where the setting lives.

An iOS feature that reduces the whole device to a few large controls. Qardbox brings its own calm interface for it: pick a subject, read the question, reveal the answer, rate, done.

Your study progress is the same as in the normal app.

Because there is no business model that needs funding. Qardbox is a personal project, built because I wanted a decent flashcard tool for myself. It earns nothing, costs nothing, and that's how it should stay.

It isn't. No investors, no subscriptions, no in-app purchases, no ads. Qardbox is built in my free time. That's not a complaint, just the honest answer.

With a review in the App Store, ideally with your own words. Without text, only a star rating counts — with words, someone who doesn't know Qardbox can judge whether it fits them.

Alternatively: tell people about it. Qardbox has no marketing and no advertising budget. Anyone who knows the app has usually heard about it from someone.

The App Store weights recent reviews more heavily. Old ratings lose visibility over time. An honest review with your own words today is more valuable than a 5-star rating from two years ago.

Also: someone looking for the app can judge from a personal experience report whether it does what it promises better than from a silent star count.