Chronograde: Watch Accuracy

Measure any mechanical watch by mic — rate, beat error, daily drift vs atomic time. Get a COSC/METAS chronometer grade and guided regulation. The Timegrapher is free.

A pro watch timing machine — right in your pocket. Chronograde reads any mechanical watch's rate and beat error through your iPhone mic, then tracks each watch's daily drift against atomic time. No dock, no $1,000 instrument.

The Timegrapher is free for everyone, with no account. Chronograde Pro removes every ad and unlocks the rest.

TIMEGRAPHER — LISTEN TO YOUR WATCH

• Rest the phone on the caseback and Chronograde "hears" the balance wheel
• Live rate in seconds per day, plus beat error in milliseconds
• Automatic beat-rate (BPH) lock-on, or set it yourself
• The same spectral-flux signal processing real timegrapher software uses — all on your iPhone or iPad

ATOMIC-TIME ACCURACY TRACKING

• Record a reading when your watch shows a target time — down to the exact second — and Chronograde compares it to NTP-synced atomic time
• Get a signed offset and a rate in seconds per day, charted over days and weeks
• Time synced from public NTP servers (Apple, Google, NTP Pool)
• Works offline using your last sync or device clock (clearly labeled)

ACCURACY BY POSITION

• Tag how the watch was kept for each reading — worn, dial up, crown down, and more
• See how the rate changes with position and the positional variation — the "delta" watchmakers use to judge regulation (Chronograde Pro)
• Combine multiple sessions to see the average rate by position over your watch's life (Chronograde Pro)

YOUR COLLECTION

• Unlimited watches with photos, brand, model, reference, serial, caliber
• A per-session drift chart for each watch — start a fresh session after a service or reset (Chronograde Pro)
• Sort by rate, last measured, last worn, or recently added
• Color-coded rate: green within ±10 s/day, orange to ±30, red beyond

WEAR & SERVICE (Chronograde Pro)

• One tap to log today's wear; days worn in the last 30 or 365 at a glance
• Full service history with provider, cost, and notes
• Set a service interval and Chronograde shows when the next one is due

ATOMIC CLOCK (Chronograde Pro)

• Large NTP-corrected clock face for setting your watch, analog and digital

DATA YOU OWN

• Optional iCloud sync across iPhone and iPad via your Apple ID
• Export your full collection to Excel or CSV; import watches from CSV (Chronograde Pro)

FREE TO START

• The Timegrapher is free for everyone — measure any watch's rate and beat error at no cost, with no account
• Record up to 10 accuracy measurements free, and keep your whole collection
• The free tier is supported by ads. They never cover the controls and never interrupt a measurement — and Chronograde Pro removes them entirely

GO PRO WHEN YOU'RE READY

• Chronograde Pro removes every ad, and adds unlimited measurements and sessions, Regulation Coach, Accuracy by Position, your Chronometer Score, the Atomic Clock, wear & service logs, and export to CSV & Excel
• Monthly or annual subscription, each with a 14-day free trial — cancel anytime, and nothing is charged during the trial
• Prefer to pay once? A one-time Lifetime unlock gives you Pro forever — no subscription

Made for watch enthusiasts who care about the seconds.

Subscription details: Chronograde Pro is offered monthly or annually after a 14-day free trial. Renews automatically until cancelled in Settings > Apple ID > Subscriptions at least 24 hours before the next billing date. Payment is charged to your Apple ID.

Terms: https://www.apple.com/legal/internet-services/itunes/dev/stdeula/ Privacy: https://mwsupplylimited.github.io/chronograde/privacy.html