iPhone Screenshots


This app detects the RPM of an electric motor based on the sound or vibration it makes, and from the RPM it calculates the percent of full load on the motor. This app does not work with all electric motors. This app only works if the motor is making a clear tonal sound or vibration whose pitch is related to the speed of the motor. It will not work if the sound is atonal or masked by too much noise. Please download the manual from our support website


to understand the limitations of this app before buying it. There is also a video showing how it works.

Although valid results may sometimes be obtained with the built-in microphone in iOS devices, in some cases better results can be obtained with an external contact microphone, such as the ones used to tune guitars in a noisy environment. By clipping a contact microphone somewhere on the motor the vibrations from the motor can be sensed directly with less noise.

Monitoring the RPM of a motor over time can be a useful preventative maintenance tool for motors used in critical industrial applications.

AC induction motors run at a speed somewhat below their synchronous speed. The degree of slippage from synchronous speed depends on the mechanical loading of that motor. When the loading increases, this app can detect the slight drop in motor speed and indicate when loading is increasing.

What’s New

Version 1.1

This app has been updated by Apple to use the latest Apple signing certificate.

* iOS sound compatibility issue fixed.
* Configuration for harmonics of motor sound added.
* Signal analysis algorithm improvement for higher accuracy in RPM measurements.
* Improved help pages.

App Privacy

The developer, Real-Time Specialties, has not provided details about its privacy practices and handling of data to Apple.

No Details Provided

The developer will be required to provide privacy details when they submit their next app update.


  • Family Sharing

    Up to six family members will be able to use this app with Family Sharing enabled.

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