What are some alternatives?
When comparing GetHarmony.net and UltimateGuitar.com, you can also consider the following products
yalp.io - Automatic chords extraction from mp3 and YouTube
ChordU - Extracts chords from any song, integrated YouTube.
Chordify - Chordify turns any music or song (YouTube, Deezer, SoundCloud, MP3) into chords.
Guitar Dashboard - Open-source interactive music theory for guitarists.
GUITAA - Turn ANY song into chords, play along with interactive chords and diagram, transpose, loop, tempo control.
Amazing Slow Downer - !A slow down music software for Mac and Windows computers - Amazing Slow Downer