My work is teach play music.
I always thought that good practice tool .
also for myself and student.
Thats it.
This is learning scale tool for Bass.
You can see below tones ,
Scale
Chord tone
Customize fret board .
and ,this tool have modulation work.
there can hear sound by tap.
if you want print ,can use printer.
series --
ukulele , guitar ,bass, piano
you can search by app store!