Magic Playlist - Get the playlist of your dreams based on a song
Lark Player - Lark Player – YouTube Music & Free MP3 Top Player is a fine tool developed by Mobiuspace Tech Top Player.
Spotalike - Spotify playlist with similar songs, according to Last.fm
Audiomack - The free SoundCloud alternative
Playlist Machinery - Tools that help you create & organize your Spotify playlists
Musicolet - Musicolet is a small yet feature-rich offline Music Player for Android.