Playlist Machinery - Tools that help you create & organize your Spotify playlists
The Eternal Jukebox - For when your favorite song just isn't long enough
Playlistor - Convert Apple Music playlists to Spotify and vice versa
The Wub Machine - Turn any music into Dubstep, Drum & Bass, and more.
FreeYourMusic - Migrate from and to any music services
YOU.DJ - Mix SoundCloud music and Youtube videos live in your browser.