Perfect Ear - A simple yet advanced application for improving your solfege skills.
Listening Ear Trainer - Listening Ear Trainer has 2 methods to improve your pitch recognition skills. The Singing Funnel Method lets you sing notes with increasing precision. The Octave Anchor Pitches Method builds a repertoire of notes, which increases with each exercise.
EarMaster - Professional software for ear training and practical music theory on Windows and Mac.
GitHub Audio - Tracks events across GitHub to generate calming work music
Meludia - Listening exercises and to sharpen your ear and music theory skills
GNU Solfege - GNU Solfege is free music education software.