Rejected-project-help : The changes are not enough. I will need you to significantly improve the UI

hello ,
This time, my application was rejected on my second attempt although I have made adjustments but it is not enough

This is a demo project android studio + java :
http://www.mediafire.com/file/pi08r2kgle7rohp/app-debug_book.apk/file

Thank you all for answers.

rename activities to meaningful names.
put comments in your java code.
so that your code will understandable