iPhone Screenshots


Want to know the precise frequency of a signal or the visual shape of a signal? Then you’ve come to the right app. Use your device’s microphone to see waveform, frequency and even the musical note of a signal in real time with Frequency Counter.

What’s New

Version 2.1

Bug fixes and various tweaks.

Ratings and Reviews

2.9 out of 5
8 Ratings

8 Ratings

Dog boy 4 ,

Frequency Counter

Although I seldom review an App, I was so intrigued by the Frequency Counter Pro that I had to comment. I tested this counter on an iPhone-4 as well as the newest iPad using iOS6. I found the displayed frequency to be quite accurate between approximately 75 and 2000 Hz. Beyond 2kHz, the display began to show errors, but interestingly these were harmonically related to the test frequencies. For example, a 4000 Hz tone may display as 2000, or a 2800 Hz test tone may display 400 Hz (2800 being the seventh harmonic of 400) perhaps. Maybe Cat Eater, the developer can explain this more thoroughly?

Other than this quirk, the graphics are clear and simple, with a retro oscilloscope look. I am however puzzled by the red indicator lamp below the display. It looks like the power on/off button on an Apple computer, but does nothing if you touch that area of the screen. The only touch screen user interface is to control the amplitude of the displayed signal. For example, if you we're sampling a quiet audio signal, you would set the amplitude to the high mode, while low mode may be best for loud or noisy environments.

My only wish, besides showing actual frequency up to perhaps 10 kHz, would be a display hold button. Bottom line is that the App is interesting to play with, and would be useful in several areas where you need to identify an audio tone or musical note.

Cliff K.

Ron_Calif ,

Testing my home made wind chimes

I bought this to measure the frequency of the tones from a five-tube wind chime I made. My iPhone is a 5C.

The 'scope display is of little use, but the frequency shown below the 'scope is stable and spot on. My design was tp produce and E note at 659 Hz; this app measured it at 658 Hz; damned good. I found no other app that offered the measurement of an arbitrary frequency. ANd this was only $0.99

I wonder if the other reviewers that faulted this app have a defective mic.

cfbrush4 ,


I needed a frequency counter to measure the resonant frequency of wine glasses for a science project. Part of our experiment is to break them by playing the resonant frequency back at high amplitude. I tried some other apps but they rounded the frequency and were pretty inaccurate. This one is extremely accurate. Mind you this is all it does (plus displaying a waveform), but it does it well, so five stars.


13 MB

Requires iOS 9.0 or later. Compatible with iPhone, iPad, and iPod touch.


English, French, German, Italian, Japanese, Korean, Portuguese, Russian, Simplified Chinese, Spanish

Age Rating


  • Family Sharing

    With Family Sharing set up, up to six family members can use this app.

More By This Developer

You May Also Like