Some suggestions

I have been using it for a month now. Still using it and I think its helping but I have a few suggestions: sampling rate - the graphical feedback sometimes indicates an instantaneous jump in frequency that is definitely not happening. This could be due to low sampling rate causing frequency aliasing; label the scale that is being displayed/practiced; make the pause button a little more functional. I dont know if its due to size or position or something about how the button is monitored but it is very difficult to successfully pause the exercise in the brief time between scales.

Ex Tabs user about Vanido - Your personal singing coach, v0.4.0