Comparison

Kello vs PFremote2

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

PFremote2

Control your acoustic player piano's playback, volume, and all other functions remotely. Connects automatically via Wi-Fi to your Pianoforce Performance Player. An offline view is available to demonstrate functionality.

Highlights
  • Remote playback control
  • Volume level adjustment
  • Control all player piano functions
  • Automatic Wi-Fi connection
  • Offline demonstration mode
Features
Read full description

The remote control for the Pianoforce Performance player allows you to control the playback, volume levels and all other functions of your acoustic player piano. It automatically connects to Your player piano through Wi-Fi. Note: To use this service - You NEED to have the Pianoforce Performance Player (www.pianoforce.com) V2.50+ connection to LAN and one Wi-Fi access point for iPhone/iPod Touch connection. Or you can press the offline view to see how it works.

Screenshots

Kello3 screens
PFremote21 screens

Verdict

The call

The clearest difference is price: PFremote2 at Free against Kello's $9.99. PFremote2 also leads on update cadence (every 5 weeks vs every 3 months) and iOS requirement (9.0 vs 13.0). Kello's advantage is rating (2.8 vs 1.7) and review sentiment (37% vs 0%). On ratings volume, 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

PFremote2 is free to download; Kello costs $9.99 up front. Neither carries in-app purchases, so what you see is what you pay.

ReceptionRating · Positive reviews · Number of ratings

Kello holds the better App Store score, 2.8 against 1.7. Both are backed by a comparable volume of ratings — 5 and 3 respectively. Written reviews point the same way: 37% of Kello's written reviews are positive against 0% of PFremote2's.

UpkeepUpdate frequency

Kello ships an update every 3 months, PFremote2 every 5 weeks. The most recent releases landed on October 10, 2026 and September 24, 2026 respectively.

Scorecard5 real differences · 5 level
Kello versus PFremote2: the parameters behind the verdict, then further details
ParameterKelloPFremote2
Price$9.99Free — better
Rating2.8 (5 ratings) — better1.7 (3 ratings)
Positive reviews37.3% of reviews — better0.0% of reviews
Number of ratings5 — better3
Update frequencyEvery 3 monthsEvery 5 weeks — better
AdsNoNo
In-app purchasesNoNo
MonetizationFreeFree
DevicesiPhone, iPodiPhone, iPad, iPod — better
Requires iOS13.09.0 — better
Further details — not scored
Size4 MB7 MB
Age rating4+4+
DeveloperColdflower Design Corp.Pianoforce

Customer experience

Kello

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

PFremote2

All ratings3 ratings
Positive0.0%
Neutral33.3%
Negative66.7%
Written reviews1 reviews
Positive0.0%
Neutral0.0%
Negative100.0%

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

PFremote2

Not enough reviews yet to summarise bugs or requests.

In-app purchases

None

Kello

No in-app purchases

None

PFremote2

No in-app purchases

Questions

Is Kello free?
Kello costs $9.99, with no in-app purchases.
Is PFremote2 free?
PFremote2 is free to download, with no in-app purchases.
Which has better reviews, Kello or PFremote2?
Kello is rated higher. Kello averages 2.8 out of 5 from 5 ratings, while PFremote2 averages 1.7 from 3 ratings.
Do Kello or PFremote2 have ads?
Neither Kello nor PFremote2 shows ads.
Which is updated more often, Kello or PFremote2?
Kello ships an update every 3 months, and PFremote2 every 5 weeks. Most recently, Kello was updated on October 10, 2026 and PFremote2 on September 24, 2026.

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