Noizio - Feeling that the noise of the big city is too much for you to bear?
Odio - Create GIFs with live audio
CSS Galore - Rich collection of css generators with live preview.
Radio4000 - Radio4000 lets you discover user curated radios from around the world, manage your online music...
Spotify - Map shows when two people play same song at same time
Endel.io - Personalized sounds to help you focus and relax