why my android app rejected , what is the problem in my UI?

I want to sell my ecommerce android app source code but my app was rejected with this comment " I will need you to significantly improve the UI of the application. It looks too barebones right now. I’m not asking for utter sophistication, just acceptable levels of refinement. If this were a class or a snippet, I wouldn’t mind if it had a bad looking demo but since this is a complete system I have to take every facet of it into account.
Unfortunately, I feel your item, in its current state, looks and behaves in a rather generic manner. With more unique features, I’d definitely be happy to take another look at this. "
how to solve this problem and this part of app’s screenshots?