Playlist Machinery - Tools that help you create & organize your Spotify playlists
Audioship - Upload audio to YouTube or Facebook
Playlistor - Convert Apple Music playlists to Spotify and vice versa
TunesToTube - What does TunesToTube do?
playAppleMusic.com - An (unofficial) web player for Apple Music
podsync - Simple and free service that lets you listen to any YouTube or Vimeo channels, playlists or user videos in podcast format