To be honest both are inferior to just keeping tabs open on your phones' internet browser. One for the Sport daily races, and the other one linking to your official profile.
This way I can see the daily races, my notifications, and my activity feed quickly and seamlessly without having to open another app. I can also manage my followers, search the Discover section, and several other things neither Apps will do.
The unofficial app will make you watch a 10 second add to see daily races, and it doesn't include notifications or activity feeds. The Official app makes you click "sign in" every time you open it. So to reiterate, both are inferior to the 2-tabs browser method, IMO..