I do not know if what I am going to suggest is even possible but I think it would be good, first for the mobile app would be to be able to chat change activity etc.
Also it would be good to add some kind of statuses like discord.
And the other not if it is even possible but it sounds good, and is some way to be able to request access to a friend and be able to see from their perspective, I do not see it possible but useful.