Ember

Spaced-repetition flashcards with SM-2 algorithm and retention tracking.

Learningflashcardsspaced-repetitionstudysm-2learningFreeShipped 2mo ago

Overview

About this app

Recall Stack is a spaced-repetition study app that helps you retain information longer by scheduling reviews at optimal intervals. Create decks of flashcards, then study due cards in focused sessions. The app uses the SM-2 algorithm to adjust each card's review interval based on your performance. Grade each card from 0 to 3, and the system automatically calculates when you should see it next. Import cards quickly by pasting front|back pairs from your clipboard. Track your progress with retention curves and daily review forecasts in the stats view. Customize daily limits and starting ease factors in settings.

How to use

Create a new deck
Go to the deck list and tap Create Deck. Enter a name and optional description, then save.
Add cards to your deck
Open a deck and tap Add Card. Enter the front (question) and back (answer) text, optionally add tags, then save.
Import cards from clipboard
Copy lines formatted as 'front | back' to your clipboard. Open a deck, tap Import, and paste. All lines are added as new cards at once.
Start a study session
Tap Study to enter the session. You will see cards that are due for review. Tap Show Answer to reveal the back, then grade yourself 0 (again), 1 (hard), 2 (good), or 3 (easy).
Review your progress
Go to Stats to see your retention curve over time and a forecast of due cards per day. Adjust your daily limits in Settings if needed.
Manage your cards
In a deck, tap any card to edit or delete it. Use tags to organize and filter cards within a deck.

More screenshots

Study session with card and grade controls

Settings for daily limits and ease factor

Demo data

On first use, no cards are seeded. Create a deck and add cards manually or import from clipboard. Each card starts with a due date of now and an interval of 0 days. After your first grade, the SM-2 algorithm computes the next interval and due date.

Privacy

User data stored: decks (name, description, color, created_at, updated_at), cards (front, back, tags, created_at), card_states (due_at, interval_days, ease_factor, repetitions, lapses, last_reviewed_at), review_logs (grade, prev_interval, new_interval, prev_ease, new_ease, reviewed_at), settings (daily_new_limit, daily_review_limit, starting_ease). All data is retained indefinitely until the user deletes a deck or card.

Changelog

Initial release. Spaced-repetition study with SM-2 algorithm, deck and card management, clipboard import, study sessions with grading, retention stats, and customizable daily limits.

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