/Favorites - Slick player for Soundcloud favorites
Magic Playlist - Get the playlist of your dreams based on a song
DaftCloud - DaftCloud is a free and wonderful designed SoundCloud App for macOS.
Spotalike - Spotify playlist with similar songs, according to Last.fm
Hermes - Pandora Client for OS X
Playlist Machinery - Tools that help you create & organize your Spotify playlists