Mightytext - Send & Receive SMS Text Messages from your computer. Sync'd with your Android #
EarMaster - Professional software for ear training and practical music theory on Windows and Mac.
Zeplin - Collaboration app for UI designers & frontend developers
Meludia - Listening exercises and to sharpen your ear and music theory skills
ActiveWords - Auto correct on steroids
GNU Solfege - GNU Solfege is free music education software.