Daily reviewers: new vs returning
Reviewers are grouped as new on their first review day or returning if they reviewed before. A review is counted when someone chooses Again, Hard, Good, or Easy on a card.
ReturningNew
Review date
Free & open source
Create cards.
Review smarter.
Remember more.
Free, open-source flashcards that schedule each review for the right time, work offline, and sync across the web, iOS, and Android. Use AI when you want help creating or improving cards. Nibomo was formerly known as Flashcards Open Source App.
No credit card. No ads. No trial countdown.
FOR PEOPLE
FOR AI AGENTS
Connect your AI agent over MCP: add the Nibomo server to Claude, Cursor, or any MCP client and it can read, create, and edit your cards.
Add this MCP server to your AI client:
https://mcp.flashcards-open-source-app.com/mcpAPP PREVIEW
Activity
Nibomo activity
See aggregate daily review activity across web, iOS, and Android. Published figures are aggregate counts and do not expose card content, email addresses, or individual study histories.
Total reviews
61,577
Reviewers
491
Days in range
195
Peak daily volume
1,655
Peak daily unique users
41
Daily reviews by platform
A review is counted when someone chooses Again, Hard, Good, or Easy on a card. Counts are grouped by platform.
WebAndroidiOS
Review date
Smarter Reviews with FSRS
Review the cards that are due today. FSRS brings difficult cards back sooner and waits longer before showing familiar ones again.
AI-Assisted Card Creation
Ask AI to help create cards, improve their wording, or clarify an answer. You stay in control of what gets saved.
Offline Study with Automatic Sync
Keep reviewing on your mobile device without an internet connection. Changes sync automatically so you can continue on the web, iOS, or Android.
Import, Export, and Own Your Data
Move your learning materials in or out whenever you like. Portable exports include your cards, tags, and related media.
Works with AI Agents
Connect through MCP or the Agent API so AI agents can help create, improve, and organize your cards.
Free and Self-Hostable
Use the hosted app for free, inspect the open-source code, or run it on your own infrastructure.