Chord NOTE is a Song writer’s assistant tool.
You can find some chords match your melody.
Chord NOTE find some chords contains some notes.

You wrote new melody came into your mind, but you could not apply some chords for your melody…
Like this time, you can find some chords by this Chord NOTE.

If you composed some songs already, you know almost melody and chord have same note. Because notes in melody are contains in the chord.
And the same reason, you can find your song’s key by Chord NOTE. Because notes in melody are contains in the key.

So Chord NOTE is very useful for finding the chord and key.

You can read full function description at support page.
http://therootage.com/iphone/chord-note-en/