ClockMaster vs ChronoLog
Price, ratings, monetisation and update history for both apps, side by side — with what reviewers say about each.
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.
- 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)
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>>> 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
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.
- 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
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ChronoLog — Timegrapher, Watch Accuracy Tracker & Collection Log Turn your iPhone into a timegrapher. ChronoLog listens to your mechanical watch through the microphone and reads its rate in seconds per day — then keeps measuring over days and weeks, on your wrist, so you know how the watch really runs, not just how it ran on the bench. No subscription. No account. One-time purchase unlocks everything. AUDIO TIMEGRAPHER • Rate in seconds per day from your watch's tick, in about 30 seconds — the same number a timegrapher gives you. • Every reading carries a confidence score, so you know when to trust it and when to record again. • Movements from 18,000 to 36,000 bph, detected automatically or set per watch. ACCURACY OVER TIME — THE PART A TIMEGRAPHER CAN'T DO A bench reading captures one moment. ChronoLog logs every measurement into timing runs and charts the daily rate as you actually wear the watch: watch it drift, catch magnetization, and see when it needs regulation or a service — before it costs you minutes a week. • Photo offset: photograph the dial against atomic time for the most precise manual reading. • Tap timing: tap on the second for a quick log with any watch, quartz included. • Tag measurements by position, temperature or activity to learn what moves the rate. ACCURACY REPORT — NEW A health score for every watch, timekeeping trends per run, and an anonymous comparison against the same models worldwide — find out whether your Submariner or your SKX keeps time better than most. Share a private report link that expires on its own. ATOMIC TIME Every measurement is referenced to NTP atomic time, not your phone's clock. Use the live atomic clock, with an optional seconds tick, to set your watches to the second. YOUR COLLECTION, ORGANISED • Unlimited watches with photos, brand, model, calibre, serial number, service history and notes. • Wear log: swipe to mark what you're wearing, then see your rotation as a calendar, timeline and stats. • Moon phase: last and next full moon with the days between — set a moonphase complication in seconds. • Full backup and restore. CSV export for your records or your watchmaker. WHY COLLECTORS CHOOSE CHRONOLOG A timegrapher is for adjusting a watch. ChronoLog is for knowing it — clean, fast, ad-free, built by a collector in Boulder, Colorado, who reads and answers every review. Download ChronoLog and find out how your watches really run.
Screenshots
Verdict
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
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.
ChronoLog holds the better App Store score, 4.6 against 3.8. Both are backed by a comparable volume of ratings — 52 and 230 respectively. Written reviews point the same way: 59% of ClockMaster's written reviews are positive against 85% of ChronoLog's.
ClockMaster ships an update every 5 months, ChronoLog every 3 weeks. The most recent releases landed on October 23, 2026 and October 24, 2026 respectively.
| Parameter | ClockMaster | ChronoLog |
|---|---|---|
| Price | $49.99 | Free — better |
| Rating | 3.8 (52 ratings) | 4.6 (230 ratings) — better |
| Positive reviews | 58.6% of reviews | 85.0% of reviews — better |
| Number of ratings | 52 | 230 — better |
| Update frequency | Every 5 months | Every 3 weeks — better |
| Ads | No | No |
| In-app purchases | Yes | Yes |
| Monetization | Free with in-app purchases — better | Paid |
| Devices | iPhone | iPhone, iPad, iPod — better |
| Requires iOS | 18.0 | 15.0 — better |
| Further details — not scored | ||
| Size | 5 MB | 50 MB |
| Age rating | 4+ | 4+ |
| Developer | ONYX Apps | tyler wood |
Customer experience
ClockMaster
ChronoLog
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
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- 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 moreShow fewer
- 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
ClockMaster
- ClockMaster Pro$29.99
ChronoLog
- Premium$5.99
- Premium$6.99
Questions
Is ClockMaster free?
Is ChronoLog free?
Which has better reviews, ClockMaster or ChronoLog?
Do ClockMaster or ChronoLog have ads?
Which is updated more often, ClockMaster or ChronoLog?
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