Comparison

Kello vs Watch Tuner Timegrapher

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

Head to head
About

Kello

This app analyzes the accuracy of mechanical watches by listening to their ticking sounds through your device's microphone. It compares the watch's rhythm to the precise system clock to reveal timekeeping differences. Supports a wide range of watch frequencies and offers guidance on identifying mechanical timepieces.

Highlights
  • Microphone-based watch sound analysis
  • Comparison to iOS system clock
  • Automatic detection of 8 common watch frequencies
  • Guidance on identifying mechanical watches
  • Displays timekeeping differences
Features
Read full description

Kello analyzes the precision of mechanical watches against the iOS system clock using a microphone. How Kello works: All mechanically regulated watches are designed to start and stop 1000s of times every hour. A portion of the energy used during this starting and stopping motion is released as acoustic energy, resulting in an audible "tick-tock" sound. The regularity of this sound can be measured against the more precise, internal time-signal of iOS devices, such as the iPhone, and the resulting difference in timekeeping is displayed by Kello. Supported Watch Frequencies: Kello can automatically determine the frequency of the watch being measured based on eight of the most common frequencies used in mechanical watches. These frequencies are standard among low-, middle- and high-grade mechanical timepieces and will accommodate the vast majority of mechanical watches produced in the past 100 years. The following frequencies are supported: * 14,400 bph * 16,200 bph * 18,000 bph * 19,800 bph * 21,600 bph * 25,200 bph * 28,800 bph * 36,000 bph Recommended hardware: Kello works best with an external microphone that has an excellent frequency response between 10,000 and 20,000 Hz. How to know if your watch is mechanically regulated: There are four simple ways to determine if your watch is mechanical and can be used with Kello. 1. Look at the text on your timepiece. If the word "quartz" is featured anywhere on the watch, your watch is not mechanical. If the words "automatic" or "shock-proof" are written anywhere on the watch, there is a very high chance that your watch is mechanical and its precision can be measured by Kello. 2. If your watch has a hand that indicates the seconds, observe how frequently it moves. If the hand moves only once every second, it is very likely that your watch is not mechanical. If this hand moves several times per second or appears to sweep along in a smooth, continuous motion, your watch is most likely mechanical and its precision can be measured by Kello. 3. Turn the crown, that is used to set the hands of the watch, while it is pressed fully in. If the crown turns smoothly, your watch is not mechanical. If you can hear a ratcheting sound as you turn the crown, your watch is most likely mechanical and its precision can be measured by Kello. 4. Place the watch close to your ear and listen. If you hear a noise approximately once every second, it is unlikely that your watch is mechanical. If you hear a constant ticking noise, your watch is very likely a mechanical watch and its precision can be measured by Kello.

About

Watch Tuner Timegrapher

This application analyzes the performance of mechanical watches by using your device's microphone to record ticking sounds. It generates a frequency diagram and provides measurements for rate, beat error, amplitude, and beats per hour.

Highlights
  • Frequency diagram display
  • Measures rate accuracy
  • Measures beat error
  • Measures amplitude
  • Measures beats per hour (BPH)
  • Uses device microphone
Features
Read full description

Watch Tuner Timegrapher is an app for testing mechanical watches — both automatic and manual winding. It displays a frequency diagram of your watch and measures the rate, beat error, amplitude, and beats per hour (BPH). The app uses your device’s built-in microphone or a headset mic to record the audible ticks of the watch. For best results, use the app in a quiet environment. Background noise can affect accuracy — complete silence works best, though the built-in noise-cancelling algorithm can filter out minor sounds. The microphone must be in contact with the watch to clearly capture the ticking sound; ideally, place it against the watch’s crown during recording.

Screenshots

Kello3 screens
Watch Tuner Timegrapher4 screens

Verdict

The call

The clearest difference is rating: Watch Tuner Timegrapher at 3.8 against Kello's 2.8. Watch Tuner Timegrapher also leads on price ($1.99 vs $9.99) and review sentiment (68% vs 37%). Kello's advantage is iOS requirement (13.0 vs 15.6). On update cadence, ads, 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

Kello costs $9.99 and Watch Tuner Timegrapher $1.99 up front. Neither carries in-app purchases, so what you see is what you pay.

ReceptionRating · Positive reviews · Number of ratings

Watch Tuner Timegrapher holds the better App Store score, 3.8 against 2.8. That said, the two scores are not equally well evidenced: Watch Tuner Timegrapher has 80 ratings behind it against 5, so its average is the more settled of the two. Written reviews point the same way: 37% of Kello's written reviews are positive against 68% of Watch Tuner Timegrapher's.

UpkeepUpdate frequency

Kello ships an update every 3 months, Watch Tuner Timegrapher every 4 months. Both last shipped on November 1, 2026.

Scorecard5 real differences · 5 level
Kello versus Watch Tuner Timegrapher: the parameters behind the verdict, then further details
ParameterKelloWatch Tuner Timegrapher
Price$9.99$1.99 — better
Rating2.8 (5 ratings)3.8 (80 ratings) — better
Positive reviews37.3% of reviews68.4% of reviews — better
Number of ratings580 — better
Update frequencyEvery 3 months — betterEvery 4 months
AdsNoNo
In-app purchasesNoNo
MonetizationFreeFree
DevicesiPhone, iPodiPhone, iPad, iPod — better
Requires iOS13.0 — better15.6
Further details — not scored
Size4 MB2 MB
Age rating4+4+
DeveloperColdflower Design Corp.Bartlomiej Swiatek

Customer experience

Kello

All ratings5 ratings
Positive40.0%
Neutral20.0%
Negative40.0%
Written reviews161 reviews
Positive37.3%
Neutral8.1%
Negative54.7%

Watch Tuner Timegrapher

All ratings80 ratings
Positive66.3%
Neutral10.0%
Negative23.8%
Written reviews196 reviews
Positive68.4%
Neutral7.1%
Negative24.5%

User reviews

Kello

From 5 App Store ratings

What we love

  • 💡 Innovative watch timing solution at affordable price
  • ✅ Accurate readings when properly configured
  • 🎯 Correctly identifies beat frequency (BPH)
  • ⚙️ Useful for watch regulation and adjustment
  • 📱 Portable alternative to expensive timing machines

Room to improve

  • 🎙️ Highly sensitive to microphone quality and placement
  • 🔇 Requires extremely quiet environment to function
  • 📊 Inconsistent readings even in same position
  • ⚠️ Frequent signal detection failures
  • 🔄 High variability in results between measurements

Watch Tuner Timegrapher

From 80 App Store ratings

What we love

  • 💰 Affordable alternative to expensive professional timegraphers
  • 📊 Accurate measurements when used correctly with proper microphone setup
  • 🎯 Precise beat error and amplitude detection capabilities
  • ⚙️ Highly adjustable settings for different watch movements
  • 📈 Clear, easy-to-read graphical display of results

Room to improve

  • 🎤 Highly dependent on microphone quality and placement
  • 🔇 Requires completely silent environment to function properly
  • ⚠️ Inconsistent readings across different devices and setups
  • 😤 Steep learning curve with many trial-and-error adjustments needed
  • 🚫 Fails to detect watch ticks in noisy environments

Bugs and requests

Kello

Reported bugs

10 issues
  • App crashes on iPhone 5 and iOS 6
  • Signal detection fails inconsistently
  • Frequency auto-detection varies wildly on same watch
  • Unstable signal readings despite strong initial signal
  • App hangs on 'determine frequency' step
Show 5 more
  • Poor microphone compatibility with external mics
  • Results vary significantly between consecutive measurements
  • Crashes frequently during measurement process
  • Incompatibility with newer iOS versions
  • Microphone not detected on some devices

Requested features

10 requests
  • History log and data storage for watches
  • Graphical representation of timing data over time
  • Average readings over longer time periods
  • Watch profile saving functionality
  • Beat error measurement capability
Show 5 more
  • Export feature for timing results
  • Fine-tuning control for amplification slider
  • Improved signal detection algorithm
  • Better microphone sensitivity recommendations
  • Compatibility with more iOS versions

Watch Tuner Timegrapher

Reported bugs

11 issues
  • App crashes on certain iOS versions (iPhone X with iOS 14.6)
  • Incompatible with older devices (iPod Touch 6, iOS 8.4)
  • Blank white screen on some devices
  • Quality reporting inconsistency between live reading and saved history
  • Cannot store more than 16 history files (save button grays out)
Show 6 more
  • Doesn't work properly with Samsung headsets on iPad
  • External microphone recognized but won't provide/analyze data
  • Auto-detect mode fails to recognize BPH correctly
  • App becomes unresponsive and requires phone restart
  • Incompatibility with latest iOS versions for audio spectrum analysis
  • Microphone collection starts immediately on app launch

Requested features

13 requests
  • Audio monitoring function to optimize microphone placement before measuring
  • Audible ticking sound output (like professional models)
  • Extended beat rate range to include mechanical clocks
  • Only request microphone permissions when actually measuring
  • History feature to save and track measurements over time
Show 8 more
  • Ability to share graphs as photos or export to email
  • Larger display for complete timestamp visibility
  • Increased history file storage (currently limited to 16 files)
  • Korean language support
  • Japanese language support
  • Dedicated hardware microphone option
  • Better auto-detection for BPH to avoid manual input
  • Ability to add watch information and photos to measurements

In-app purchases

None

Kello

No in-app purchases

None

Watch Tuner Timegrapher

No in-app purchases

Questions

Is Kello free?
Kello costs $9.99, with no in-app purchases.
Is Watch Tuner Timegrapher free?
Watch Tuner Timegrapher costs $1.99, with no in-app purchases.
Which has better reviews, Kello or Watch Tuner Timegrapher?
Watch Tuner Timegrapher is rated higher. Kello averages 2.8 out of 5 from 5 ratings, while Watch Tuner Timegrapher averages 3.8 from 80 ratings.
Do Kello or Watch Tuner Timegrapher have ads?
Neither Kello nor Watch Tuner Timegrapher shows ads.
Which is updated more often, Kello or Watch Tuner Timegrapher?
Kello ships an update every 3 months, and Watch Tuner Timegrapher every 4 months. Most recently, Kello was updated on November 1, 2026 and Watch Tuner Timegrapher on November 1, 2026.

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