This is an interesting concept by a man called Frank Geiger. Made for instruments tuned in fifth. He writes, that it doesnt require reading music, knowledge of key signatures or chord spellings. Looks interesting. If you try it please comment, if it is useful for players of bouzouki.
http://www.calgaryuke.com/ukerichard/tenor/Chord%20Builder%20For%20Fifths%20Tuned%20Instruments.pdf
