EDIT: The only reason why I still had it at this point was because I could use it with other apps. However, now that my Spotify Subscription is cancelled, it doesn't work with anything. It's mildly infuriating because today, I can't still use it with other apps like I was able to yesterday.
Please don't make the same mistake I made. No one should buy this.
Offline mode on spotify is local media with extra steps. Offline mode is premium only. Also you still get tracked with the proprietary app. Spotify songs cannot be played in your favourite music player, device or whatever. I can copy some songs into sdcard to play it on an old speaker set.
Pirated music gets more convenient than what you paid for. Moreover, restricting saving and sharing media is kinda dumb and does not actually hurt artists or their revenue