The simple user interface with noise filtering can help you tuning strings with simple setting while activating the APP. First step is choose the frequency at top of screen, then choose tuning mode at the middle of the screen. When you pull the string, the pitch will be shown on the panel for the individual string by indicating signal high or low. 
 [Function Description] ▪ A4 Frequency adjustment: choose 428~452 frequencies for A4 string. ▪ The scale for precision tuning is 10 cents for every sub-bit. The brown line represents the open strings start from. The green arrow means pitch is accurate and it will turn white once the pitch difference exceeds more than a sub-bit. ▪ The complete function, will visually tell you the pitch is good or not by lighting green or white. Users can easily adjust the string by the lighting arrow shown on the scale.