In this post I will present a UX issue from a very famous engineer cultured company.
Every user interface should be developed in such manner that it is self descriptive. It should be self documented, so menu items or input fields should have labels that clearly describe their purpose. Tooltips must not be some fancy technology, but they should contains small pieces of business logic that describe how is this part of form connected with business logic.
Icons should also have that purpose. If I want to save something, please put floppy disk icon (thank you Microsoft for that mnemonic).
And then we have Android back icon. What is first mental image in your head when you see that icon? What is the purpose of that icon?
For me: I will first go right in menu, and when I get there, Android will AUTOMATICALLY make a U turn and then I will go to the left in application menu.