Be smart, and when someone asks you "what's E7sus4?", impress them with your knowledge! Handy when that awkward chord pops up at a jam, and you're too embarrased to ask, or don't want to be seen with a chord chart in front of you...

Step through chords in the same note by tapping the note on the top left, or step through to other notes by tapping the grid. Fancy inversions are accessed using the 'up' button, and some 'special' chords by the 'down' button.