Chronograde

Track how fast or slow your watch runs. Version 1.0

About

Chronograde measures and logs the accuracy of your mechanical, quartz, or smart watches against true atomic time. Record a reading when your watch reads a target HH:MM, and Chronograde compares it to NTP-synced time to compute a signed offset and a rate in seconds per day. Add as many watches as you like, see drift over time on a chart, log wear and service history, and export everything to CSV or Excel. No accounts, no ads, no tracking.

Getting started

Add a watch with the + button. Brand and model are required; everything else (reference, serial, caliber, purchase price, photo) is optional.
Pull-to-sync atomic time from the toolbar. Chronograde talks to public NTP servers (time.apple.com, time.google.com, pool.ntp.org) to correct for any device-clock drift.
Tap Record Measurement. Pick the time your watch is about to show (e.g. 14:30) and press the red RECORD button at that instant.
Watch the drift chart fill in after your second measurement. Average rate per day and current offset are computed automatically.
Log wear with one tap on the detail screen. The wear log tracks days worn over time. Log service with type, provider, cost, and notes — set a service interval and the detail screen will show when the next one is due.
Switch themes under Settings → Theme Shop. Two themes are free; the rest are one-time purchases.

FAQ

What counts as an "accurate" measurement?

Chronograde uses SNTP (RFC 4330) to query the network time service and applies the resulting offset to your device's clock. In practice this is accurate to well under a tenth of a second — far finer than the human eye can read off a watch dial. The bottleneck is your reaction time pressing RECORD at the moment the second hand touches the target. Press it consistently and the math averages out over multiple readings.

What's a good rate?

It depends on the watch. COSC chronometer-certified mechanical watches must run within −4/+6 seconds per day. ETA standard movements typically run ±10–30 s/day. Quartz watches usually run ±0.5 s/day or better. Chronograde colors the rate green up to ±10 s/day, orange up to ±30, and red beyond that.

The sync button shows "Could not reach a time server."

Chronograde uses UDP on port 123 for SNTP queries. Some corporate, hotel, or captive Wi-Fi networks block outbound UDP. Try a different network or use cellular, then tap the sync icon in the top-right of the Watches tab. Without a successful sync, measurements fall back to the device clock and are marked accordingly.

How does Watch Accuracy Pro work?

You can record up to 10 measurements across all watches for free. Watch Accuracy Pro is a monthly subscription that removes the cap. New subscribers get a 7-day free trial, then it renews at $1.99 per month until cancelled. Manage or cancel anytime from iOS Settings → [your name] → Subscriptions. Tap Restore Purchases in the app if you've subscribed before on the same Apple ID.

Does it sync between my iPhone and iPad?

If iCloud (CloudKit) is enabled for Chronograde and you're signed in with the same Apple ID on both devices, your watches, measurements, wear log, and service history will sync automatically. Settings → iCloud shows the current status.

Can I export my data?

Yes. From the Watches tab menu, choose Export to Excel (workbook with Watches, Measurements, Wear, Service sheets) or Export to CSV. You can also import a watches CSV the same way; Chronograde detects duplicates by serial number or brand + model + nickname.

I found a bug or have a feature request.

Please email mwsupplylimited@gmail.com with your iOS version, device, and steps to reproduce. We read every message.

Contact

For support: mwsupplylimited@gmail.com

Privacy

See the Chronograde Privacy Policy.