Barcaddy
Stop fumbling through a stack of plastic cards at the checkout. Scan once, then pull up the barcode whenever a cashier asks — offline, on your device, and nowhere else.
Barcaddy holds the barcodes you actually need in front of a cashier: loyalty cards, membership IDs, coupons. Scan any 1D or 2D code once, label it, and pull it up full-screen at the till. That is the whole product.
The reason it exists is that most apps in this category want an account, a cloud sync and a look at your shopping habits — for a job that is a lookup table and a picture of a barcode. Barcaddy collects, transmits and shares nothing. It asks for exactly one permission, the camera, and only to scan a new card; you can type the digits in by hand instead. Everything is stored on the device, and CSV export means moving to a new phone does not mean starting again.
Then there are the small details that decide whether a utility is actually usable. Screen goes to full brightness while a code is on screen, because supermarket scanners struggle with dim displays. Auto-off is suppressed while you are holding the phone out. Per-card background and foreground colours, so you can find the right one without reading. It follows the system theme, light or dark.
Written in Kotlin, public on GitHub under active development, not yet published to the Play Store. Like wbtl.app, it is built with a spec-first, agent-assisted workflow — and it is the everyday test of that method: a real app, on a real phone, used in a real queue.