I haven’t tried using it for bass guitar but I believe it should just work? I assume you want tabs for bass guitar. Alphatab, the tablature editor supports bass guitar and other stringed instruments too. I guess it even supports notation for drums/percussion.

For that matter, I think the app should work for practicing any instrument that can be practiced with a metronome if you ignore tablature (which is only for reference anyway).

For now I want focus on guitar as that’s my primary use case but I’d love to extend it for other instruments in future.