Nertz Score
iPhone score keeper for the card game Nertz (also called Nerts, Pounce, or Racing Demon). Works offline, with no accounts and no server.
Details →← All workSoftware · iPhone and Android app
Book Spotter
Point your phone at a bookshelf and it finds the books you are looking for.
Live on the App Store and Google PlayStatus as of November 12, 2026
Published on both stores, with its own site at bookspotter.app.
What it does
One spine among several hundred
Book Spotter reads the spines on a shelf through the camera and draws a box around every title on your list, in real time. It was built for the places where finding one book means reading several hundred spines: used bookstores, libraries, estate sales, and reseller sourcing trips.
All of the text recognition runs on the phone. No photos and no text leave the device, and it keeps working with no signal in the back corner of a bookstore.
- Live text recognition with a box over each matching spine: yellow for a close match, green for a confident one
- A FOUND banner, with an optional vibration, so you can scan a shelf without staring at the screen
- Search for several titles at once, or for an author on their own
- A book list you can also manage from a web page on a computer
- Free for up to five books, with three monthly Search Plus plans above that
At a glance
- Status
- Live on the App Store and Google Play
- Platforms
- iPhone (iOS 17 and later) and Android
- Price
- Free, with optional monthly subscriptions
- Privacy
- Recognition runs on the device
- Links
- bookspotter.app, App Store, Google Play
Built with
- SwiftUI
- AVFoundation and Vision
- StoreKit 2
- Kotlin and Jetpack Compose
- CameraX and ML Kit
- Play Billing
- Cloudflare Workers, Hono, and D1
- Cloudflare Pages
More software
Other things we have built
ThriftSpotter
iPhone app for resellers: photograph a thrift-store shelf or an estate-sale table and it flags anything likely to resell above your minimum price.
Details →Tally Hour
Time tracker for Mac, iPhone, and the browser, synced through one small server. We run the business on it every day.
Details →Call Review
Offline tool for investigators: it transcribes a jail-call export on a workstation with no internet and builds a searchable review report that opens in any browser.
Details →Need software like this built?
We scope it, build it, test it properly, and keep it running. You deal with the engineer who writes the code.
