Spaced. vs Lumen

Remember what you learn, one card at a time. Spaced. is a minimalist flashcard app for iPhone and iPad. Create decks for languages, classes, trivia, lyrics, work concepts, or anything else you want to keep in memory. Review with spaced repetition, and Spaced. brings each card back when it matters most. Why Spaced.? • Study less, remember more Cards you know well come back later. Cards you miss return sooner. Your sessions stay focused on what needs attention. • Simple, fast reviews Flip a card, recall the answer, then swipe right if you remembered or left if you missed it. No clutter, streak pressure, or complicated setup. • Make the decks you actually need Create your own collections, decks, and cards with text, images, and audio. Reorder things, search decks, and track progress per deck. • AI-assisted deck creation Use an AI assistant you already have to draft a deck. Paste the JSON into Spaced., review the cards, and add it to your library. Spaced. does not run AI inference or require an AI account. • Starter decks included Begin with built-in French, Indonesian, and Japanese decks, including Japanese kana with pronunciation audio. • Private by design No ads. No tracking. No Spaced. account. Your user-created decks and progress stay on your device and can sync through your private iCloud account. Spaced. is free to use, with optional one-time tips for people who want to support development.

Lumen is a flashcard app for people who want spaced repetition to work properly and want their data to stay on their phone. Cards are scheduled with FSRS-6, the algorithm that models memory as difficulty, stability, and retrievability rather than a fixed ladder of intervals. Every rating button shows the interval it would give you before you tap it, so you can see what Again, Hard, Good, and Easy actually cost. If you want to tune the scheduler, all 21 FSRS weights and your desired retention are editable, with bounds checking so you cannot save a set that breaks scheduling. BRING THE DECKS YOU ALREADY HAVE Import from Anki .apkg files, Anki JSON, CSV and TSV, Markdown, and Lumen's own ZIP backups. Anki's rendered HTML is stripped on the way in, so you get clean card faces instead of stray markup. Imports are idempotent: re-importing a deck or overlapping HSK levels will not duplicate anything. You can export your decks at any time. BUILT FOR CHINESE, USEFUL FOR EVERYTHING The HSK importer reads the complete-hsk-vocabulary dataset and keeps every written form, numeric pinyin, radical, and frequency rank. Chinese notes render tone-colored pinyin alongside simplified and traditional forms, meanings, part of speech, HSK level, and classifiers. Each word can generate both recognition and production cards. Text-to-speech reads cards aloud, and the spoken language is set per deck. For everything else there are Basic, Basic and Reversed, and Cloze note types, Markdown formatting on card faces, nested decks at any depth, image and audio attachments, and full-text search across your collection. YOUR CARDS STAY ON YOUR DEVICE Lumen works offline and has no accounts. Your decks, notes, review history, and media live in a database on your phone, and nothing syncs to a server. Lumen reports anonymous usage and crash data so bugs get fixed, and that reporting excludes deck names, tag names, note contents, search queries, and file paths. Settings has a reset that erases everything locally. KEEPING THE HABIT A daily goal, streaks, XP, and achievements track consistency. The stats screen shows review counts, retention, daily accuracy, rating distribution, how card difficulty is trending, and a heatmap of your study activity. You can share a streak or heatmap card as an image without sharing the cards themselves. Lumen has no ads and nothing to unlock by paying.