NOISESUPPLY - Pandora for SoundCloud
Gnoosic - Even if you don't know what you are looking for - gnod will find it.
Move to Apple Music - Convert your Spotify playlists for Apple Music
Musicroamer - A visual Pandora for discovering new music
Tune My Music - Transfer Playlists Between Music Services
Songstack - Swipe to discover new music for Spotify