Measure any mechanical watch with your iPhone: rate, beat error, and drift against atomic time. The Timegrapher is free — Chronograde Pro removes every ad.
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
- 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
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 7-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.
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Subscription details: Chronograde Pro is offered monthly or annually after a 7-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
Ratings & Reviews
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• The iCloud screen now tells you the truth. If something on this device hasn't reached iCloud, you'll see it said plainly instead of a green tick — along with the date of the last successful upload, rather than the last time anything synced at all. A watch owner spotted that those two can be very different things, and he was right.
• Fixed: a watch with a photo attached could never upload to iCloud. If you've added photos, those watches should start syncing again.
• A sync warning no longer vanishes when you reopen the app, so a problem that needs your attention stays put until it's genuinely resolved.
• "Sync Now" now tells you what it actually did, instead of spinning for a moment and leaving you to guess.
• The record count on the iCloud screen is now labelled "Records on this device", because that is what it has always counted.
Version 1.6.3
The developer, Matthew Wong, indicated that the app’s privacy practices may include handling of data as described below. For more information, see the developer’s privacy policy .
Data Used to Track You
The following data may be used to track you across apps and websites owned by other companies:
Location
Identifiers
Usage Data
Data Not Linked to You
The following data may be collected but it is not linked to your identity:
Location
Identifiers
Usage Data
Diagnostics
Privacy practices may vary, for example, based on the features you use or your age. Learn More
Accessibility
The developer has not yet indicated which accessibility features this app supports. Learn More
Information
Seller
Matthew Wong
Size
10.5 MB
Category
Utilities
Compatibility
Requires iOS 17.0 or later.
iPhone Requires iOS 17.0 or later.
iPad Requires iPadOS 17.0 or later.
Mac Requires macOS 14.0 or later and a Mac with Apple M1 chip or later.