Comparison

ClockMaster vs AtomicClock

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

Head to head
About

ClockMaster

This app analyzes the ticking sound of mechanical pendulum clocks to determine their running rate and error. It's designed for accurate long-term measurements, allowing users to regulate clocks efficiently. Advanced features include printable reports and data export for in-depth analysis.

Highlights
  • Analyzes escapement ticking sound
  • Measures running rate in Beats Per Hour (B/H)
  • Reports error in Seconds Per Day (±S/D)
  • Supports long-term measurements
  • Generates printable PDF reports (Pro)
  • Exports raw data as .csv file (Pro)
Features
Read full description

>>> Check out the demo videos at ClockMasterApp.com ClockMaster is a clock timing software, in many ways similar to watch timegraphers, but specifically designed to work with mechanical pendulum clocks. The app analyzes the ticking sound of the escapement to determine the clock's running rate measured in Beats Per Hour (B/H). This rate is then compared to a specified Target Rate, and the Error is reported as Seconds Per Day fast or slow (±S/D). The speed of a mechanical pendulum clock is not constant, fluctuating with age and wear, spring tension and even temperature. The ClockMaster app was created with a focus on accurate long-term measurements where traditional timers often do not function very well. For the professional horologist or interested amateur, you can now test in the field — put the clock in exact beat and regulate the clock with just a few hours of testing. For increased rate accuracy and in depth investigation of clock movement's behavior, you can conduct long-term measurements for up to two weeks (ClockMaster Pro). Branded, printable PDF reports can be generated for each measurement, and the raw data exported as .csv file for graphing in a spreadsheet (ClockMaster Pro). ClockMaster Pro (in-app upgrade) provides these additional features: • Save and share branded, printable PDF reports for each measurement • Export raw measurement data as a .csv file for spreadsheet analysis • Conduct long-term measurements of up to two weeks

About

AtomicClock

This app displays the exact current time synchronized with NTP servers, offering a customizable clock view for precise time checks. It's ideal for setting watches, verifying timestamps, or comparing local and network time.

Highlights
  • Precise time from NTP servers
  • Customizable clock faces
  • Select or add time servers
  • Local and UTC views
  • 12/24 hour modes
  • Customizable time format
  • Acoustic ticking
Features
Read full description

Check precise NTP reference time at a glance. AtomicClock helps you set watches, wall clocks, cameras, and other devices, compare local time with UTC, and follow moments when every second matters. Clear analog and digital time AtomicClock displays current time from NTP servers that reference atomic clocks. Choose a predefined server or add your own, then view local or UTC time in a clean analog or digital clock. Customize your reference clock • Switch between 12-hour and 24-hour time • Customize the time format • Choose from multiple clock faces and hands • Use a smooth, fluid second hand • Add acoustic ticking or the Greenwich Time Signal • Tap the screen to hide information and controls, freeze the display, or mute ticking Details for precise time checks View technical NTP information, including round-trip time and server stratum. Whether you are checking a timestamp, preparing a camera, aligning a wall clock, or setting a watch by hand, the seconds remain clear and easy to follow. AtomicClock is free to use. AtomicClock Pro is available as a one-time purchase with no subscription. It unlocks your preferred clock face, hands, and font, removes ads, and includes upcoming Pro features. AtomicClock displays NTP reference time for comparison and does not change your device’s system time. Results can vary with the selected server, network conditions, and device behavior.

Screenshots

ClockMaster4 screens
AtomicClock4 screens

Verdict

The call

The clearest difference is price: AtomicClock at Free against ClockMaster's $49.99. AtomicClock also leads on rating (4.8 vs 3.8) and update cadence (every 3 weeks vs every 5 months). ClockMaster's advantage is ads (none vs shown). On in-app purchases and monetization model 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

AtomicClock is free to download; ClockMaster costs $49.99 up front. ClockMaster sells 1 one-off in-app purchase and AtomicClock 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

AtomicClock holds the better App Store score, 4.8 against 3.8. That said, the two scores are not equally well evidenced: AtomicClock has 5.5K ratings behind it against 52, so its average is the more settled of the two. Written reviews point the same way: 59% of ClockMaster's written reviews are positive against 85% of AtomicClock's.

UpkeepUpdate frequency

ClockMaster ships an update every 5 months, AtomicClock every 3 weeks. The most recent releases landed on September 23, 2026 and September 24, 2026 respectively.

Scorecard8 real differences · 2 level
ClockMaster versus AtomicClock: the parameters behind the verdict, then further details
ParameterClockMasterAtomicClock
Price$49.99Free — better
Rating3.8 (52 ratings)4.8 (5.5K ratings) — better
Positive reviews58.6% of reviews84.5% of reviews — better
Number of ratings525.5K — better
Update frequencyEvery 5 monthsEvery 3 weeks — better
AdsNo — betterYes
In-app purchasesYesYes
MonetizationFree with in-app purchasesFree with in-app purchases
DevicesiPhoneiPhone, iPad, iPod — better
Requires iOS18.015.0 — better
Further details — not scored
Size5 MB17 MB
Age rating4+4+
DeveloperONYX AppsTimo Partl

Customer experience

ClockMaster

All ratings52 ratings
Positive71.2%
Neutral5.8%
Negative23.1%
Written reviews70 reviews
Positive58.6%
Neutral5.7%
Negative35.7%

AtomicClock

All ratings5,539 ratings
Positive96.5%
Neutral1.8%
Negative1.8%
Written reviews239 reviews
Positive84.5%
Neutral3.3%
Negative12.1%

User reviews

ClockMaster

From 52 App Store ratings

What we love

  • 👍 Works very well
  • 👍 Accurately sets beat and calibrates time
  • 👍 Good alternative to expensive dedicated instruments
  • 👍 Elegant display for setting beat and symmetry
  • 👍 Works well for professional clock repairers

Room to improve

  • 😞 Frustrating data handling
  • 😞 Spreadsheet export issues
  • 😞 iPhone notifications stop measurements
  • 😞 Does not work for 400-day clocks
  • 😞 External mic option missing

AtomicClock

From 5.5K App Store ratings

What we love

  • 🚀 Accurate time
  • 👍 Highly customizable
  • 🚀 Precise to the second
  • 👍 Easy to use
  • 👍 Helpful for setting watches

Room to improve

  • 🐛 Server connection issues
  • 🔍 Limited time zone options
  • 💰 Ads diminish clock view
  • 🔍 Lacks some advanced features
  • 🔍 Redundant for some users

Bugs and requests

ClockMaster

Reported bugs

6 issues
  • Data lost if app stops unexpectedly
  • iPhone notifications interrupt measurements
  • External mic option not available
  • App freezes after iOS upgrade
  • Screen touch points unresponsive
Show 1 more
  • Help section incomplete

Requested features

13 requests
  • Printable protocol like a timegrapher
  • Beat delta info on regulation screen
  • Option to manually restart measurement and append
  • Undocumented units in spreadsheet export
  • Include actual time in spreadsheet export
Show 8 more
  • Ability to set BPH to 480 for 400-day clocks
  • Plots for drift rate and periodic error within the app
  • Mic that works with the app
  • External mic option
  • More detailed graphs
  • Option to upgrade for $5 instead of $20
  • Better GUI and interface
  • Indication of which half of the cycle is longer/shorter

AtomicClock

Reported bugs

3 issues
  • Crashes on certain iOS versions
  • Occasional freezing of hands
  • Countdown timer sound not working

Requested features

5 requests
  • Add GMT/dual time display
  • Implement widget support
  • Add different second hand sounds
  • Allow setting background color to match watch
  • Include alarm/timer functionality

In-app purchases

1 purchases

ClockMaster

One-time1
  • ClockMaster Pro$29.99
1 purchases

AtomicClock

One-time1
  • Lifetime Pro Version$6.99

Questions

Is ClockMaster free?
ClockMaster costs $49.99, and also offers in-app purchases.
Is AtomicClock free?
AtomicClock is free to download, with in-app purchases available.
Which has better reviews, ClockMaster or AtomicClock?
AtomicClock is rated higher. ClockMaster averages 3.8 out of 5 from 52 ratings, while AtomicClock averages 4.8 from 5.5K ratings.
Do ClockMaster or AtomicClock have ads?
AtomicClock shows ads; ClockMaster does not.
Which is updated more often, ClockMaster or AtomicClock?
ClockMaster ships an update every 5 months, and AtomicClock every 3 weeks. Most recently, ClockMaster was updated on September 23, 2026 and AtomicClock on September 24, 2026.

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