Harmonic Sense has released ChordMate for Mac OS X, an app that is designed to make it easy to choose chords for guitar.
Choosing the right chord—and the right voicing for that chord—can transform a song. Whether you are a beginner worried about stretching your fingers to the right frets or a professional musician looking for just the right sound, ChordMate will find the chord voicing that is right for you. Just select the chord you want, and ChordMate will list all of the possible voicings, sorted either by quality, ease of play, or a bit of both.
The results are customized based on the type of guitar: classical, acoustic, jazz, or electric. You can even listen to how the chord would sound on your guitar.
Advanced features include a rule editor and a chord symbol lookup tool.