Isochron: Watch Accuracy

Worn accuracy now comes with an honest margin of error — and stays quiet when your photos can't support a number yet. Plus sharper dial shots and bench-versus-wrist.

Rest your iPhone against your watch and watch its rate appear live — like a bench timegrapher, without the bench.

MEASURE LIKE A WATCHMAKER • Daily rate (s/day) and beat error in about 30 seconds, with a live scrolling beat trace • Amplitude from your caliber’s true lift angle (Pro) • Guided position tests with a chronometer-style report (Pro) • Overnight stability runs — drift across the power reserve (Pro) • Magnetism check using your iPhone’s sensors (Pro)

MEASURE LIFE ON THE WRIST A bench reading tells you how a watch runs on a table. Isochron’s photo method tells you how it runs on your wrist: photograph the dial, we timestamp it against atomic time, and the drift between photos is your real worn accuracy.

YOUR COLLECTION, DOCUMENTED Every watch with photos, specs, serials, full accuracy history, service records, warranty reminders, wear rotation — and a polished PDF insurance report (Pro).

COMPARE WITH EVERY OTHER OWNER Your reading lands on the live distribution for your exact model and movement. Better than 84% of Submariner owners? Now you know. Then talk shop in caliber-specific forum boards.

FAIR PRICING, NO SUBSCRIPTION Measuring, your collection, the photo method, and the community are free — forever. The bench instruments are one single purchase. No subscription, ever.

PRIVATE BY DESIGN Audio is analyzed on-device and never uploaded. No ads, no tracking.

IAP — Isochron Pro: “Isochron Pro” / “Amplitude, position tests, overnight runs, magnetism check, and the insurance report. One purchase, yours forever.”