Ability to see your rank, league, winning percentage, plays, achievements etc. at the “homepage”. Maybe also a feature where you get to see all the leagues and their corresponding ranks, i suggest the leader-board to be in-game in the future as well to encourage more competitive playing. In addition, being able to check stats while waiting for arena games would be even better (i don’t imagine this to be easily implemented).
Also, I would replace the “person” icon that you use to go to the shop with a shopping bag icon.