I would highly recommend downloading and installing DCIntrospect[0]. It's designed to let you tweak layout in the simulator, but what it's really useful for is probing the UI in large, complex apps. Need to tweak the font size on a specific element, but you have no idea what that view class is? Enable DCIntrospect, click on the element, log its class name and properties. This has saved me, literally, hundreds of hours of debugging time over the years.

[0] https://github.com/domesticcatsoftware/DCIntrospect