Ratewell: Watch Timegrapher

Your iPhone is now a precision timegrapher. Measure rate, amplitude and beat error, then track every watch's accuracy over time. Free to measure, forever.

Ratewell turns your iPhone into a precision timegrapher for mechanical watches. Hold your watch to the microphone and read rate, amplitude and beat error in seconds — the same measurements a watchmaker's machine gives you, without the costly hardware.

But a single reading is only the start. Ratewell logs every measurement to build the one thing other apps don't: a long-term accuracy history for each watch in your collection.

MEASURE LIKE A WATCHMAKER

• Live timegrapher: rate (seconds/day), amplitude and beat error from your microphone
• Calibrated signal detection that stays steady through ambient noise
• Six-position analysis: dial up/down, crown left/right and more — see positional variance and isochronism
• Chronometer (COSC) tolerance reference so you instantly know if a reading is in spec

TRACK ACCURACY OVER TIME

• Automatic rate-history chart per watch — every measurement, plotted
• Spot drift and regulation issues before they cost you a service
• Compare positions, sessions and trends across your whole collection

A REAL COLLECTION & SERVICE BOOK

• Unlimited watches: brand, model, caliber, reference, purchase date, photos
• Service log and reminders: last service, interval, warranty, power reserve
• Wear tracking and rotation — know what you wear and what sits idle
• Export a clean PDF accuracy certificate or CSV for your watchmaker

YOURS, EVERYWHERE

• iCloud sync and backup across iPhone and iPad
• Home-screen widgets for today's rate and the next service due
• Designed dark-first, like a real timing machine, with tabular figures throughout

FREE TO MEASURE — ALWAYS The timegrapher and the data you save are never locked behind a paywall. Measure, log and read your full history for free, forever.

RATEWELL PRO Unlock the complete instrument: unlimited watches, six-position analysis, isochronism and long-term trends, service reminders, wear tracking, iCloud sync, widgets and export.

• Monthly or Annual subscription — the Annual plan includes a 7-day free trial
• Or pay once with Lifetime — no subscription, ever

Built for collectors who care about precision, from a vintage automatic to a modern chronometer.

— Ratewell Pro is an auto-renewable subscription. Payment is charged to your Apple ID at confirmation of purchase. The subscription renews automatically unless it is cancelled at least 24 hours before the end of the current period; your account is charged for renewal within 24 hours before the period ends. Manage or cancel your subscription anytime in your App Store account settings. A Lifetime one-time purchase is also available. Any unused portion of a free trial is forfeited when you buy a subscription.

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