This isn't your garden variety chord app. It shows the whole fretboard with color coded (by scale tone) chord tones. It's awesome. Not the prettiest app, per se, but really functional. [tips hat to the author]. It also offers several standard chord diagrams as well if the fretboard view is intimidating (although it shouldn't be!).

I have been playing this instrument for about five years, and I wish I had an app like this from the beginning. So far it seems really easy to use, and very helpful. :)