Magic Playlist - Get the playlist of your dreams based on a song
MagicPattern - The best design toolbox with 10+ tools for anyone
Spotalike - Spotify playlist with similar songs, according to Last.fm
Isometric - Create beautiful, abstract works of art & optical illusions
Playlist Machinery - Tools that help you create & organize your Spotify playlists
Isometric Game Art Pack - Extensive library of game art for indie devs