Yes, exactly as the topic says you can get Spotify Premium for life without any Subscription or ad in either app or Spotify itself!
You’ll find more information at spotify.hko.sesuch as proof via mobile screen record ⏺ when I’m using the App with full premium functionality but Spotify still says
”Free version – upgrade to Premium”. That’s bescuse it’s a totally legit but modified version of Spotify. You can still use your same login and your playlists and all will be there. Full premium – no costs!