Isaac Companion
An offline encyclopedia for The Binding of Isaac — 900+ items, trinkets and bosses in your pocket, with on-device screenshot recognition.
iOS 18+ · SwiftUI · Core ML · Free, no ads
Why I Built It
Every Isaac run ends the same way: pause, pull out my phone, google the item I just picked up, scroll past a wall of text to find the one line I needed — then come back and forget what I was doing. The wiki is great, but it's built for browsers, not for the 30 seconds between item pickups.
What It Does
- Complete offline data — 900+ items, 189 trinkets and 99 bosses with structured effects, unlock conditions and DLC filters, all bundled. Zero network needed.
- Screenshot recognition — point the camera at your game screen and an on-device Core ML model (MobileNetV3, 711 classes, trained on item icons) tells you what you just picked up.
- Fuzzy search — type 'momsb' and find Mom's Box.
- Built-in translation — item effects translated on-device via Apple Intelligence (English / 简体中文 / 繁體中文).
- Item quiz — a 10-round guessing game to learn the item pool between runs.
- I'm Feeling Lucky — roll a D6 to jump to a random item, trinket or boss.
How We Built It
The data pipeline scrapes the community Rebirth wiki (wiki.gg) and cleans years of MediaWiki template markup into structured JSON — preserving bullet lists, phase sections and per-DLC values. A Core ML model trained on 700+ item icons powers the screenshot recognition, running entirely on-device. The app itself is native SwiftUI with light/dark mode, multiple app icons and full offline support.
Challenges
Turning messy MediaWiki templates into structured JSON without destroying bullet and phase formatting took several iterations. The item classifier's second retrain regressed on real-world screenshots — I shipped v1 and kept the backup instead of chasing a worse model.
What's Next
- App Store release after TestFlight beta feedback
- Android version
- Recognition model improvements with real-world screenshot validation
Published: 2026-09-10