NOISESUPPLY - Pandora for SoundCloud
TubeLister - Generate a YouTube playlist from your opened tabs.
OrganizeTube - Create video playlists from Youtube, Vimeo and other sources
Vidlis - Create music playlists from YouTube videos.
Playlist Machinery - Tools that help you create & organize your Spotify playlists
NewPipe - NewPipe is a lightweight YouTube front-end for Android.