Prep Tracker
A spaced-repetition study app that works offline and tells you what to review next.
- 6
- Review intervals, 1 to 60 days
- 499
- Automated tests
- 4.0
- Graduate GPA while using it
Ever noticed how you learn something and a few weeks later it's just gone? Now imagine having to learn hundreds of concepts in a time crunch. There's a science-backed way to trick your brain into remembering: active recall and spaced repetition. Thirty minutes a day for 30 days beats cramming for hours the night before the exam, by a lot. That's why I built Prep Tracker!
What it is
Prep Tracker logs what you studied and schedules when to see it again. I built it for my own interview prep and coursework, used it throughout my master's, and opened it up once other people started asking for it. It has 10 users now.
How it works
Every card sits on one of six review intervals, from 1 to 60 days. Answers stay hidden until you reveal them, you grade yourself, and a card you get right moves to a longer interval while one you struggle with steps back. Subjects are configurable in settings, so the same app covers algorithms, system design, or exam vocabulary.
Built to work offline
Reads come from a local IndexedDB store, so the app opens instantly and keeps working without a connection. Logging an attempt takes a few seconds, and an offline write queue sends each attempt with an idempotency key, so a retry never counts it twice.
Shipping it
It runs on AWS (Lambda, CloudFront, S3, Cognito), all defined as infrastructure as code. A public demo runs the real app on sample data entirely in the browser.
