A Spotify sidebar app, along with Facebook messenger, Whatsapp Telegram and VK, that loads the spotify web [https://open.spotify.com] for being able to pin, select music and browse at the same time.
Plus, when you hover over the spotify icon when the sidebar is pinned, a miniplayer of some sort opens out giving you basic media control such as pause/previous/skip track, and the song title and maybe album artwork too.