Comparison

ClockMaster vs ChronoLog

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

ChronoLog

This app provides professional-grade tools to track the accuracy of mechanical watches. It offers audio timegraphing, photo offset measurement, and tap timing, along with detailed analytics and atomic time synchronization for collectors and enthusiasts.

Highlights
  • Audio timegrapher for rate, beat error, and amplitude
  • Photo offset measurement against atomic time
  • Tap timing for quick offset logging
  • Track accuracy trends over time
  • Atomic time synchronization
  • Detailed performance graphs and analytics
  • Manage and organize watch collection
Features
Read full description

ChronoLog — Watch Accuracy Tracker & Audio Timegrapher for Mechanical Watches Track the accuracy of your mechanical watches with professional-grade tools. ChronoLog combines an audio timegrapher, offset measurement logging, and atomic time synchronization into one app — purpose-built for watch collectors and horology enthusiasts who care about precision. No subscription. No account. One-time purchase unlocks everything. MEASURE WATCH ACCURACY — THREE WAYS • Audio Timegrapher: Use your device's microphone to listen to your watch's tick and measure rate (seconds per day), beat error, and amplitude — the same metrics a professional timegrapher provides. • Photo Offset: Photograph your watch dial against atomic time, enter the displayed time, and ChronoLog calculates the exact offset. The most precise manual method for measuring watch accuracy. • Tap Timing: Tap when your watch hits a specific second to quickly log an offset. Fast, simple, and works with any watch. TRACK ACCURACY OVER TIME Each measurement is logged to a timing run — a series of readings that ChronoLog analyzes together. Monitor your watch's daily rate, see how accuracy changes day to day, and spot regulation issues before they become problems. Tag measurements with conditions like position, temperature, or wear pattern to understand what affects your watch's performance. ATOMIC TIME SYNCHRONIZATION ChronoLog syncs with NTP atomic time servers so every measurement is referenced against true time — not your phone's clock. View the live atomic time, compare it to your device, and use it as a precision reference when setting your watches. DETAILED ANALYTICS & VISUALIZATIONS Dive into performance graphs that show rate trends, offset history, and accuracy patterns across your entire collection. See at a glance which watches in your collection are your most accurate daily wearers and which need regulation or service. BUILT FOR WATCH COLLECTORS • Add unlimited watches with photos, brand, model, serial number, caliber, and notes • Organize your collection with archive support • Export all measurement data to CSV for your records or your watchmaker • Back up and restore your full database across devices WHY CHRONOLOG? Whether you're a seasoned collector checking COSC-grade accuracy, a hobbyist curious about your Seiko's daily rate, or a watchmaker tracking regulation results — ChronoLog gives you the tools to measure, log, and understand your watch's timekeeping performance. Built by a watch enthusiast in Boulder, Colorado. Download ChronoLog and start measuring your watch accuracy today.

Screenshots

ClockMaster4 screens
ChronoLog4 screens

Verdict

The call

The clearest difference is price: ChronoLog at Free against ClockMaster's $49.99. ChronoLog also leads on rating (4.6 vs 3.8) and update cadence (every 3 weeks vs every 5 months). On ads and in-app purchases 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

ChronoLog is free to download; ClockMaster costs $49.99 up front. ClockMaster sells 1 one-off in-app purchase and ChronoLog sells 2 one-off in-app purchases. Whichever you choose, the download price is not the number that matters.

ReceptionRating · Positive reviews · Number of ratings

ChronoLog holds the better App Store score, 4.6 against 3.8. Both are backed by a comparable volume of ratings — 52 and 204 respectively. Written reviews point the same way: 59% of ClockMaster's written reviews are positive against 85% of ChronoLog's.

UpkeepUpdate frequency

ClockMaster ships an update every 5 months, ChronoLog every 3 weeks. The most recent releases landed on September 23, 2026 and September 26, 2026 respectively.

Scorecard8 real differences · 2 level
ClockMaster versus ChronoLog: the parameters behind the verdict, then further details
ParameterClockMasterChronoLog
Price$49.99Free — better
Rating3.8 (52 ratings)4.6 (204 ratings) — better
Positive reviews58.6% of reviews84.8% of reviews — better
Number of ratings52204 — better
Update frequencyEvery 5 monthsEvery 3 weeks — better
AdsNoNo
In-app purchasesYesYes
MonetizationFree with in-app purchases — betterPaid
DevicesiPhoneiPhone, iPad, iPod — better
Requires iOS18.013.0 — better
Further details — not scored
Size5 MB49 MB
Age rating4+4+
DeveloperONYX Appstyler wood

Customer experience

ClockMaster

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

ChronoLog

All ratings204 ratings
Positive91.2%
Neutral2.0%
Negative6.9%
Written reviews99 reviews
Positive84.8%
Neutral9.1%
Negative6.1%

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

ChronoLog

Not enough reviews yet to summarise bugs or requests.

In-app purchases

1 purchases

ClockMaster

One-time1
  • ClockMaster Pro$29.99
2 purchases

ChronoLog

One-time2
  • Premium$5.99
  • Premium$6.99

Questions

Is ClockMaster free?
ClockMaster costs $49.99, and also offers in-app purchases.
Is ChronoLog free?
ChronoLog is free to download, with in-app purchases available.
Which has better reviews, ClockMaster or ChronoLog?
ChronoLog is rated higher. ClockMaster averages 3.8 out of 5 from 52 ratings, while ChronoLog averages 4.6 from 204 ratings.
Do ClockMaster or ChronoLog have ads?
Neither ClockMaster nor ChronoLog shows ads.
Which is updated more often, ClockMaster or ChronoLog?
ClockMaster ships an update every 5 months, and ChronoLog every 3 weeks. Most recently, ClockMaster was updated on September 23, 2026 and ChronoLog on September 26, 2026.

Other comparisons