Playlist Machinery - Tools that help you create & organize your Spotify playlists
PRIZM - Intelligent music player that you can plug into any speakers
Playlistor - Convert Apple Music playlists to Spotify and vice versa
Magic Playlist - Get the playlist of your dreams based on a song
FreeYourMusic - Migrate from and to any music services
Tycho Forecast - Turn your weather into a Spotify or Apple Music playlist