You look for the tuning of the instrument and it spits out chord and scales for it. Pick the note and it gives you fingerings for more scales than you can shake a stick at, with the roots clearly marked. As a scale nerd I love it 
Here’s the url for standard E 4-string bass guitar:
It even has notes to play to tune to, and has a 432Hz option if you’re into that sort of thing.
Thanks for the link. I started playing around with different tunings so this will help.
lol they do not f around. I’m adding the 6-string standard tuning for bass and:
“For each new tuning submitted, the following will be created
29 chords for each key = 348 chords
16 scales for each key + access to 500 more = 692 scales”
I am not going that deep into the scale world. Just want to play some songs that use different tunings.