Chosen by Swiss brands, available for all.


ONEOF® Accuracy² -> Small, fun, powerful. For watch lovers.
ONEOF® Accuracy boutique edition -> Measures & demagnetizes simultaneously. For watch boutiques.
ONEOF® Accuracy Pro -> The new generation multi-position measurement system. For watchmakers.

For several years, we have been developing the most accurate and precise diagnostic instruments to fulfill the highest requirements of Swiss Watch Manufactures. Today, ONEOF® Accuracy gives watch aficionados the opportunity to acquire the only high-end integrated tool capable of providing a complete diagnosis of a mechanical watch on an iPhone.

Just place the crown of your watch against the ONEOF® Accuracy sensor and after a few seconds of initialization, you get all the detailed technical information about your watch in a fun and user-friendly app : beats per hour, instantaneous and average rate accuracy in seconds per day, amplitude of the balance wheel, beat error, signal analyzer as well as graph... You then have the possibility to save all the results in your watch database and share them.

What’s New

Version 3.0

Full compatibility with iOS13 & iPad Pro.
Brand new active noise cancelling algorithm.
Compatible with OMEGA co-axial escapement (note: lift angle = 37°)
New algorithms for amplitude detection, more reliable with vintage watches & tourbillons.

Ratings and Reviews

2.0 out of 5
11 Ratings

11 Ratings

mcerock ,

You need the sensor

I've read you can use your headphone/mic from your phone. Sadly, this is not the case. You can buy their sensor, but it's still cheaper to buy a real timegrapher.

Spsilvestri ,

Played with this and it seems to work!!

I know it says you need a special type of device, but I plugged in my headphones and used the mic and placed it behind my watch.... I Had a pretty good idea if I’m tracking it every day how fast or slow my watch runs. This app pretty much Verified the exact deviation that I was calculating myself simply by tracking it on a day today basis. I was also amazed by the magnetism detection... at first I thought “no way” but then I held one of my headphones up to the back is my phone (magnet from the speaker in it should detect a difference) and the thing went nuts! I don’t know how useful it is for long term tracking or actual data collection, but it seems pretty accurate to me. Better than paying for another app! Give it a try!! It’s free!

CAG_1337 ,

What a rip-off!

Just buy a real timegrapher for a small fraction of the money.

App Privacy

The developer, Jean-Charles ROUSSET, has not provided details about its privacy practices and handling of data to Apple. For more information, see the developer’s privacy policy.

No Details Provided

The developer will be required to provide privacy details when they submit their next app update.


  • Family Sharing

    With Family Sharing set up, up to six family members can use this app.

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