This Oscilloscope really is a wireless instrument designed to work from your iPhone 5S in conjunction of the Arduino Uno unit and the BlueTooth low Energy HM-10 . This application is intended for Hobbyists and Technicians who are interested in observing low frequency signals wirelessly, performing even FFT analysis.
By default the signals to be as low as 0.20 volts in magnitude and in a frequency range between 20Hz to 150Hz , but you can modify the Arduino code supplied here to enable reach higher Hz , in the Arduino Setup procedure. For measurement of Hz We have introduce a low pass filter to avoid glitches. The App counts now with Low pass and Band pass tuned filtering and the measurement of the rms values takes into account the DC value of the wave.