Twixt Time 4+

Accuracy tracker for watches

Coldflower Design Corp.

Designed for iPhone

    • 3.5 • 13 Ratings
    • $9.99

iPhone Screenshots


Twixt Time helps track the longterm accuracy of watches and clocks, by collecting & analyzing precisely timed snapshots of their dials.

Use Twixt Time to take a picture of the dial of an analog clock or watch. Each picture captures the exact time displayed on the dial. Twixt also notes the precise instant that the each snapshot was taken, by communicating with highly accurate NTP timeservers on the Internet.

A new snapshot of each timepiece can be added everyday. Using the information from 2 or more snapshots of the same timepiece, Twixt will calculate and show you how precisely the watch or clock is keeping time.

Twixt tracks the most recent rate, overall average rate, and cumulative gain or loss for each timepiece.

Supported dial configurations:

* Hour & minute hands with a central seconds hand
* Hour & minute hands with seconds displayed in a subdial
* Hour & minute hands only

Does Twixt Time work with GMT watches?

Yes. Twixt Time does not need to track the 24 hour hand of GMT watches to measure their precision. It is only necessary to track the hour, minute, and second hands. For GMT watches with central seconds, select the "central seconds" layout. For GMT watches with an offset or subdial seconds hand, select the "subdial seconds" layout. Twixt Time automatically monitors timezone changes based on the timezone setting of the iPhone or iPod touch.

Does Twixt Time work with chronograph watches?

Yes. The chronograph functions of a watch do not need to be measured to track the precision of the watch. Twixt Time tracks the precision of chronographs, as well as watches with other complications, in the exact same way that it tracks the precision of a normal, time-only watch. If the central seconds hand can be stopped and reset with the chronograph function, select the "subdial seconds" layout to track the small seconds hand with Twixt Time. If the central seconds hand continues to move when the chronograph is stopped, but the small seconds hand stops, select the "central seconds" layout to track the central seconds hand with Twixt Time. Most chronographs will use a subdial seconds layout.

Does Twixt Time work with watches that have an offset seconds hand?

Yes. For watches with a second hand that is not concentric with the hour and minute hands, select the "subdial seconds" layout.

Does Twixt Time work with quartz watches and clocks? Or other watches and clocks that are powered by batteries?

Yes. Twixt Time works with battery powered watches and clocks that display the time with an hour, minute, and/or second hand. It does not work with watches or clocks that only display the time digitally.


Twixt Time is not affiliated with or endorsed by any watch or clock brand. The timepieces shown are for demonstration purposes only.

What’s New

Version 2023.3.2

This version of Twixt Time addresses an edge case wherein the app could crash when dismissing the camera immediately after launching it.

Ratings and Reviews

3.5 out of 5
13 Ratings

13 Ratings

Wm Gardner ,

Pretty good, but only if you picture is.....

On the average, the app works pretty well. I am tracking 4 different timepieces, all with automatic movements. Once you have a few entries for that timepiece, it averages out to right at what I was calculating by hand, using an atomic clock.

The most difficult part is in taking a quality image of the face. You need even lighting, with no glare (like from a lightbulb), and you need to hold the phone "square" to the watch face. You need to be able to see every minute market, regardless of how many you have, with equal clarity and they must all be at the same angle. If you do not accomplish this, the "12:00 marker" will not line up properly and you will notice that the lines for the hands do not fall perfectly in the middle of each hand. If these do not happen, you will receive inaccurate measurements. Should you proceed, despite the problems I described, it will require several measurements before the average works out to be accurate.

ambanmba ,

This app saved me a huge headache!

I have been using Twixt for nearly a decade and recently took my watch in for a service (which thanks to Twixt was showing a slow degradation in performance over a couple of years). When I got the repaired watch back from the watchmaker something looked amiss but I couldn't tell what it was. Thanks to Twixt I was able to see photos of the watch before the service and immediately it was clear that the watchmaker had replaced the hands with slightly different ones. I never would have been able to know this without a long history of photos of the watch. It was also very easy to show the watchmaker the error since there wasn't much to argue with about the clear evidence of the incorrect hands. I was able to share screen shots with the watchmaker to show the change - an idea to improve the app would be an ability to export/import timelines. Otherwise the app has been matured to perfection as the developer has made continuous improvements to it over the years. Thanks!

CAG_1337 ,

Tedious, inaccurate

I didn't think it was possible for them to make an app worse than Kello, but they did. This is very tedious to use and very inccurate. You have to take a photo of your watch and manually locate the cetner, 12 o'clock, hour, minute and second hands on the screen...repeat to get a reading. After all that, it said a mechanical watch of mine was runnning at +12 minutes per day---which is not even in the ballpark. A real timegrapher shows it is running ~+4 seconds. Don't bother with this one.

Developer Response ,

Hi CAG_1337, We have added a lot of features since version 1.02 to assist with the positioning of the hands and would love to hear what you think of the app today. You may also find it helpful to note that it is important to capture successive Snapshots at least 24 hours apart. Snapshots that are taken less than a day apart will multiply any errors due to parallax, beat rate, and/or hand position. The purpose of the Timeline lock, which can be enabled or disabled in Settings, is to guard against such errors. For the most accurate results, it is best to wait 24 hours before adding a new Snapshot to a Timeline. If you have any questions or need further assistance, please feel most welcome to reach out via email, at


Thank you for taking the time to repost the review that you wrote back in 2013. I can only begin to imagine how frustrated you must feel. I would love to help you get the most out of Twixt Time and would be happy to investigate why you encountered the results that you did. As before, please feel most welcome to reach out to for support. Mention that you are CAG_1337 and I will attend to you personally, so that you do not need to articulate again anything that you have already here. Thank you for your passion for horology and precision. I admire it.

App Privacy

The developer, Coldflower Design Corp., 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 Not Collected

The developer does not collect any data from this app.

Privacy practices may vary, for example, based on the features you use or your age. Learn More


  • Family Sharing

    Up to six family members can use this app with Family Sharing enabled.

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