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 were 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.

Dog boy 4 about Frequency Counter Pro