Hum - Songwriting for iPhone

Songlio - Free musical guessing game: race friends to name that tune

Songcraft.io - A platform for songwriters to write, organize & collaborate.

SongTrivia2.io - Songtrivia2.io is a browser and mobile blind test game that allows you to play in real time with your friends or against strangers. Several musical themes, difficulty and game modes are available to create lots of different musical quizzes.

Horucco - Horucco is an cloud based app for musicians, songwriters, producers of every skill levelExplore chords and discover related chords on the fly.

SongPop - The world's biggest music trivia game. Now even better.