Comparison

Clockwork vs O

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

Head to head
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

About

O

Features
Read full description

O-Buddy is your smart driving companion that helps you understand how your habits behind the wheel impact your wallet. By connecting to your vehicle’s OBD device via Bluetooth, O-Buddy detects every instance of harsh braking and instantly provides detailed data on how much fuel you're consuming and how much that translates to in real money. But it doesn’t stop there — the app gives you a clear picture of your fuel usage over time, allowing you to view your consumption on a weekly, monthly, or yearly basis. With a sleek and intuitive interface, O-Buddy makes complex data easy to understand, helping you become a more efficient, cost-conscious driver. Whether you’re commuting daily or taking weekend trips, O-Buddy gives you the insight you need to drive smarter, waste less, and take control of your fuel spending — all while supporting English, Italian, and Arabic for a seamless experience across users (new languages will be added as well).

Screenshots

Clockwork4 screens
O4 screens

Verdict

The call

The clearest difference is in-app purchases: O at none against Clockwork's 1. Clockwork's advantage is iOS requirement (16.4 vs 18.2). On price, ads and device support 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. Clockwork sells 1 one-off in-app purchase. O asks for nothing beyond the download.

Scorecard2 real differences · 8 level
Clockwork versus O: the parameters behind the verdict, then further details
ParameterClockworkO
PriceFreeFree
Rating4.4 (24 ratings) — better—
Positive reviews45.5% of reviews—
Number of ratings24 — better—
Update frequencyEvery 3 weeks—
AdsNoNo
In-app purchasesYesNo — better
MonetizationFree with in-app purchases—
DevicesiPhoneiPhone, iPad — better
Requires iOS16.4 — better18.2
Further details — not scored
Size242 MB1 MB
Age rating4+4+
DeveloperAppfred ASDaniele Fontana

In-app purchases

1 purchases

Clockwork

One-time1
  • Clockwork Premium$5.99
None

O

No in-app purchases

Questions

Is Clockwork free?
Clockwork is free to download, with in-app purchases available.
Is O free?
O is free to download, with no in-app purchases.
Do Clockwork or O have ads?
Neither Clockwork nor O shows ads.

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