EarMaster - Professional software for ear training and practical music theory on Windows and Mac.
WaveBots Editor - Procedural music and sound maker that exports to Wav, MIDI, GoatTracker and much more.
Meludia - Listening exercises and to sharpen your ear and music theory skills
Abundant Music - Generate royalty free music with a simple but very powerful procedural music creator
Perfect Ear - A simple yet advanced application for improving your solfege skills.
Tape It - App for songwriting & audio recording.