Custom Tunings / Alternate Tunings

I don't play guitar.  The chords are very useful to me, but features like capo and diagrams are decidedly NOT useful features for non-guitar players.  It would be so amazing to be able to select "Custom Instrument" and choose the number of strings and the tuning for that instrument, and save it to your profile.  I would make a banjo instrument in gDGBD.

However this feature would be useful for guitar players, too.  You could make an instrument in a non-standard tuning, and the chord diagrams & capo would be relative to that tuning.