The Eternal Jukebox - For when your favorite song just isn't long enough
Songlio - Free musical guessing game: race friends to name that tune
The Wub Machine - Turn any music into Dubstep, Drum & Bass, and more.
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.
YOU.DJ - Mix SoundCloud music and Youtube videos live in your browser.
Fretello Stage - Jam, record and share your music in the blink of an eye