My main issue is with the Follower Upgrade modal overlay. You must tap the tiny X (close) target to dismiss this overlay while it’s in a lightbox. Consider allowing users to also close this overlay by tapping outside of the Follower Upgrade overlay for ease of use and larger target sizes.
While we’re talking about target sizes, navigating my equipment takes precision, too. Switching from one piece of armor to another takes a precise tap on the X (close) button, then another tap on the armor I want. I have to do this for every piece of equipment I want to upgrade at that moment.
Consider implementing a horizontal swipe as another way to switch between equipment while users upgrade different pieces at one time.