I've been a long time user on desktop as well. I was a fairly heavy user of Spotify plugins (and maybe "apps", but I didn't understand the difference). Plugins, of course, do not exist anymore. Looks like maybe about four years ago: https://community.spotify.com/t5/Desktop-Windows/No-Apps-plu...

I'm a little salty about them closing off third-party development, but it's cool, they can do what they want with their stuff. I saw the writing on the wall a while ago when they were pushing Facebook integration like crazy -- as they become more and more anti-consumer, I'll simply avail myself of their services less and less until they offer me no value.