Vidlis - Create music playlists from YouTube videos.
Playlist Machinery - Tools that help you create & organize your Spotify playlists
DiskyT - Youtube playlists done right
Playlistor - Convert Apple Music playlists to Spotify and vice versa
OrganizeTube - Create video playlists from Youtube, Vimeo and other sources
FreeYourMusic - Migrate from and to any music services