Guitaa is a free online music platform for musicians, that lets them find chords of any song of their choice on Guitar, Piano and Ukulele.
App:
Perfect app for musicians
EarMaster - Professional software for ear training and practical music theory on Windows and Mac.
ChordU - Extracts chords from any song, integrated YouTube.
Meludia - Listening exercises and to sharpen your ear and music theory skills
Chordify - Chordify turns any music or song (YouTube, Deezer, SoundCloud, MP3) into chords.
Perfect Ear - A simple yet advanced application for improving your solfege skills.
yalp.io - Automatic chords extraction from mp3 and YouTube