Comparison

Twelve O'clock vs Clockwork

Price, ratings, monetisation and update history for both apps, side by side — with what reviewers say about each.

Head to head
About

Twelve O'clock

Easily track the accuracy of your mechanical watches over time. Manually log checkpoints to calculate seconds per day and visualize performance with charts. Manage your watch collection with photos and learn more about horology.

Highlights
  • Manage watch collection
  • Add/edit/remove watches
  • Include watch photos
  • Track watch accuracy
  • Calculate seconds per day
  • View accuracy charts
  • Horology content
Features
Read full description

Twelve O’clock is an app that helps track your watch accuracy easily in a realistic way. I can’t stress this enough: it’s “tracking”, not measuring instantaneous accuracy like a timegrapher device. It’s a manual and oldschool job but it brings so much fun. It reminds me of the old days when I had to synchronize my watch to the clock on the TV at 7pm every day. With Twelve O'clock you can: ** MANAGE YOUR WATCH COLLECTION * Add, edit, remove any item in a list of your watch collection * Include a nice wristshot of each watch ** KNOW YOUR WATCH ACCURACY * Simply add some checkpoints and let the app calculate the accuracy in *second per day* * A nice chart of the accuracy over the time ** LEARN MORE ABOUT HOROLOGY * Curated content for watch lovers (like me)

About

Clockwork

This app allows you to measure the accuracy of your watches using your phone's camera. It compares an image of your watch to an atomic clock to calculate its timekeeping offset. Track accuracy over time with graphs and store detailed watch information.

Highlights
  • Measure accuracy using images
  • Atomic clock synchronization
  • Accuracy over time graphs
  • Store detailed watch information
  • Dark mode support
  • Digital and analog atomic clock
Features
Read full description

Measure the accuracy of your watches today! Clockwork includes several useful features. You can store watch information, measure watch accuracy, and set your watch using a clock synchronized with atomic time. Check it out now! _MEASUREMENTS USING IMAGES_ Most other watch measurement apps require either third-party equipment or that you press a button at a specific time. Additional equipment is often expensive, and timing a button press is difficult to do precisely. Clockwork solves this by letting you take a picture of your watch and indicate the time shown in the image. We then synchronize the image capture time with atomic time before comparing it with the time shown on the watch to calculate an offset. Taking measurements over time provides a real-world view of your watch's accuracy. _GRAPHS_ Watch your measurements over time on a beautifully crafted graph. The graph shows how your watch's accuracy changes over time and offers several modes to help you understand its performance. _WHY MEASURE?_ Knowing the accuracy of your watch is interesting on its own, but it also has several practical uses. It can indicate when it is time for a service, and documented accuracy could increase resale value, especially for vintage watches. _STORE DETAILED INFORMATION_ In case of theft or accidents, it will always help to have your information stored in a secure place. _ATOMIC CLOCK, DARK MODE AND MUCH MORE!_ Clockwork includes an atomic clock in both digital and analog formats to help you set your watch as precisely as possible. Powerful settings such as Dark or Light mode, separate day and date formats, and different ways to sort your watches let you customize the app to your liking. // Appfred AS © 2026

Screenshots

Twelve O'clock4 screens
Clockwork4 screens

Verdict

The call

Twelve O'clock and Clockwork both sit at 4.4 stars, but that hides the real split: 91% of Twelve O'clock's written reviews are positive against 43% of Clockwork's. Twelve O'clock also leads on device support (3 vs 1) and ratings volume (82 vs 24). On price, rating, update cadence and ads there is nothing between them.

Scored on Price · Rating · Positive reviews · Number of ratings · Update frequency · Ads · In-app purchases · Monetization · Best chart rank · Devices · Requires iOS

CostPrice · In-app purchases · Ads · Monetization

Both are free to download. Twelve O'clock sells 1 one-off in-app purchase and Clockwork sells 1 one-off in-app purchase. Whichever you choose, the download price is not the number that matters.

ReceptionRating · Positive reviews · Number of ratings

On the App Store both sit at effectively the same score — 4.4 for Twelve O'clock against 4.4 for Clockwork. Both are backed by a comparable volume of ratings — 82 and 24 respectively. Written reviews are what separate them: 91% of Twelve O'clock's written reviews are positive against 43% of Clockwork's.

UpkeepUpdate frequency

Both ship on a similar rhythm, roughly every 3 weeks. The most recent releases landed on August 10, 2026 and September 11, 2026 respectively.

Scorecard4 real differences · 6 level
Twelve O'clock versus Clockwork: the parameters behind the verdict, then further details
ParameterTwelve O'clockClockwork
PriceFreeFree
Rating4.4 (82 ratings) — better4.4 (24 ratings)
Positive reviews91.1% of reviews — better42.9% of reviews
Number of ratings82 — better24
Update frequencyEvery 3 weeksEvery 3 weeks
AdsNoNo
In-app purchasesYesYes
MonetizationFree with in-app purchasesFree with in-app purchases
DevicesiPhone, iPad, iPod — betteriPhone
Requires iOS14.0 — better16.4
Further details — not scored
Size45 MB242 MB
Age rating4+4+
DeveloperHieu PhamAppfred AS

Customer experience

Twelve O'clock

All ratings82 ratings
Positive84.1%
Neutral1.2%
Negative14.6%
Written reviews123 reviews
Positive91.1%
Neutral0.8%
Negative8.1%

Clockwork

All ratings23 ratings
Positive78.3%
Neutral4.3%
Negative17.4%
Written reviews28 reviews
Positive42.9%
Neutral10.7%
Negative46.4%

Bugs and requests

Twelve O'clock

Reported bugs

11 issues
  • App freezes at loading requiring phone restart
  • Data deletion after app updates
  • Data loss on app crash
  • Graph display glitches after checkpoints
  • Photo checkpoint feature returns 'old photo not supported' error
Show 6 more
  • Beeping only works when phone not in silent mode
  • Sort function not working
  • Screenshot sharing produces blank page
  • Calculation errors showing ~150 second variance
  • Checkpoint history doesn't display correctly
  • Swiping left to delete checkpoints not intuitive

Requested features

18 requests
  • iCloud/cloud synchronization across devices
  • Notifications or reminders for checkpoints
  • Current time button on checkpoint screen
  • Larger buttons for 15/30/45 second marks
  • Power reserve tracking
Show 13 more
  • Wear frequency tracking
  • Average accuracy by watch position
  • Widget support
  • Atomic clock built into app
  • Regulator clock layout for time setting
  • In-app feedback option (instead of Twitter)
  • Automatic time reading from watch photos
  • 12-hour time format option
  • Sort function improvements
  • Year display in checkpoint history
  • Chrono24 account integration
  • Regular article updates
  • Export to Excel/CSV

Clockwork

Not enough reviews yet to summarise bugs or requests.

In-app purchases

1 purchases

Twelve O'clock

One-time1
  • Twelve Plus$1.99
1 purchases

Clockwork

One-time1
  • Clockwork Premium$5.99

Questions

Is Twelve O'clock free?
Twelve O'clock is free to download, with in-app purchases available.
Is Clockwork free?
Clockwork is free to download, with in-app purchases available.
Which has better reviews, Twelve O'clock or Clockwork?
Twelve O'clock is rated higher. Twelve O'clock averages 4.4 out of 5 from 82 ratings, while Clockwork averages 4.4 from 24 ratings.
Do Twelve O'clock or Clockwork have ads?
Neither Twelve O'clock nor Clockwork shows ads.
Which is updated more often, Twelve O'clock or Clockwork?
Twelve O'clock ships an update every 3 weeks, and Clockwork every 3 weeks. Most recently, Twelve O'clock was updated on August 10, 2026 and Clockwork on September 11, 2026.

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