Fret Pet App

[Scoot]

FretPet is a guitar-oriented music sequencer with a dynamic interface that makes writing music fun and surprisingly easy. FretPet is centered around the six-string guitar, so it makes an ideal reference tool for finding the names of chords on the fretboard. The program can show you any chord in any tuning.

http://www.thinkyhead.com/

$30US - 10.3 or higher

Open the demos to see how it works.
(the play and stop controls are in the top menu)

Seems like an interesting tool.....once you get used to the layout.
(some of the windows look wrong on my Mac (like the wheel), but it is a relatively new release).