Magic Playlist - Get the playlist of your dreams based on a song
Audioship - Upload audio to YouTube or Facebook
Spotalike - Spotify playlist with similar songs, according to Last.fm
TunesToTube - What does TunesToTube do?
Playlist Machinery - Tools that help you create & organize your Spotify playlists
Tovid.io - Upload mp3 to YouTube: image and audio are rendered to video and published to your channel.