# Ratekeeper: Watch Accuracy — Measure your watch's accuracy > Measures mechanical watch accuracy using atomic time and user taps. (iPhone/iPad app by Slow Sunday Software LLC.) - Source: https://appshunter.io/ios/app/ratekeeper-watch-accuracy/id6792385277 (this page in markdown: same URL + `.md`) - Developer: [Slow Sunday Software LLC](https://appshunter.io/developer/6786411203) - Category: Utilities - Price: Free with in-app purchases - Rating: 5.00/5 from 2 App Store ratings · 2 written reviews indexed - Age rating: 4+ - Requires: iOS 26.5 · 7 MB - Languages: American English - Released: 2026-09-01 - Data updated: 2026-09-05 - Monetization: free - User reviews in markdown: https://appshunter.io/ios/app/ratekeeper-watch-accuracy/id6792385277/reviews.md ## What is Ratekeeper? Every mechanical watch has a rate — a few seconds gained or lost each day, as personal to the movement as a fingerprint. Ratekeeper tells you what yours is, exactly, without a timing machine or a trip to the watchmaker. The method is a five-second pleasure. Set your watch to true time. A day or two later, tap the screen the instant the second hand crosses twelve. Ratekeeper compares that tap to atomic network time — accurate to hundredths of a second — and, from two readings, works out the watch's rate in seconds per day. Gaining or losing, and by exactly how much. That's the whole thing. No microphone, no cradle, no gear. Just your watch, your phone, and a tap. WHAT YOU SEE • The rate, plainly. "+5.4 spd" — and, in words, "gains 5.4 seconds a day," so the sign never has to be decoded. • A history that reads like a story. Every reading is grouped into runs — a run begins each time you set the watch — and charted so you can watch a rate settle in as a fresh service beds down, or drift as it comes due for one. • Against a band, if you want one. Hold a watch to −4/+6 seconds a day, or the tighter 0/+5, and see at a glance whether it's keeping to spec. • By resting position. Dial up, crown down, on the wrist — a mechanical watch runs differently in each. Ratekeeper breaks the rate down position by position and even suggests how to rest it tonight to bring it closer to true. • A true-time reference clock. A standalone screen showing network time to the tenth of a second, so you can set any watch against it. BUILT FOR PEOPLE WHO CARE ABOUT WATCHES • Manual, automatic, quartz, or something else — each is measured on its own terms. • Gentle reminders on your rhythm, so readings land a few days apart the way the math wants. • Export every reading to CSV whenever you like — the data is yours to keep. PRIVATE BY DEFAULT No account. No sign-up. No ads. Your watches and readings live on your device and sync across your own devices through your own private iCloud — we can't see them, and nobody is building a profile out of your collection. Find out how your watches really run. Every one of them has a rate — this is how you learn it. Have questions? We're here to help. Email us at hello@slowsundaysoftware.com Terms of Use: https://slowsundaysoftware.com/terms Privacy Policy: https://slowsundaysoftware.com/privacy ## Key features - Measures watch rate in seconds per day - Historical data tracking and charting - Comparison against specified accuracy bands - Analysis of rate by resting position - Standalone true-time reference clock - Export readings to CSV ## Pricing and in-app purchases Base price: Free. **One-time purchases** | Purchase | Price | Type | | --- | --- | --- | | Unlock the entire app | $4.99 | one-time | ## Recent user reviews (2 of 2) All indexed reviews: https://appshunter.io/ios/app/ratekeeper-watch-accuracy/id6792385277/reviews.md ### 5/5 — Clean, accurate, and no subscription *2026-09-02* Really well-made app. UI is super clean, no ads, and it doesn't force you into an account or a monthly fee. Just paid the one-time unlock to add the rest of my collection. Highly recommend if you care about your watch accuracy. ### 5/5 — Great tool! *2026-09-02* As an owner of a few watches that I rotate, this is so helpful to ensure they are synced and ready to go. I found out that one of them had significant drift and was losing eight seconds a day, which means I probably need to service it. Now I can ensure they are in the best possible condition. App is simple and easy to use. ## Frequently asked questions about Ratekeeper ### How does Ratekeeper measure watch accuracy? Ratekeeper uses a simple method: you tap the screen when your watch's second hand aligns with true atomic time. The app then compares this tap to the atomic network time, accurate to hundredths of a second, to calculate your watch's rate in seconds per day. ### Does Ratekeeper have ads? No, Ratekeeper is ad-free. The app is designed to be private by default, with no ads and no data collection. ### What devices does Ratekeeper support? Ratekeeper is available for iPhone and iPad devices. ### Can I export my watch accuracy data from Ratekeeper? Yes, you can export every reading to CSV format whenever you like, ensuring you keep your data. ### How often is Ratekeeper updated? The latest version is 1.0.1, last updated on September 2, 2026. While specific update frequency isn't detailed, the app is actively maintained. ### What is the age rating for Ratekeeper? Ratekeeper has an age rating of 4+, making it suitable for a wide range of users. ### Does Ratekeeper require an account or sign-up? No, Ratekeeper is private by default and does not require an account or sign-up. Your data stays on your device and syncs privately via iCloud. ### Can Ratekeeper help me adjust my watch's resting position? Yes, Ratekeeper breaks down the rate by resting position (dial up, crown down, etc.) and can suggest how to rest your watch to improve its accuracy. ## Version history (last 2 releases) ### 1.0.1 — 2026-09-02 Regulated a few bugs out of the movement. Ratekeeper should run a little closer to spec now. ### 1.0.0 — 2026-09-01 No release notes. ## More apps by Slow Sunday Software LLC - [Patina: Home Maintenance](https://appshunter.io/ios/app/patina-home-maintenance/id6790560083) - [Nanea: Unguided Meditation](https://appshunter.io/ios/app/nanea-unguided-meditation/id6790560686) All apps by Slow Sunday Software LLC: https://appshunter.io/developer/6786411203 --- *Data collected daily from the US App Store and indexed by [AppsHunter](https://appshunter.io/). User reviews are verbatim App Store reviews. Ratings, prices and chart positions refresh continuously; this snapshot is from 2026-09-05.*