Guidance for our android app which got rejection

Hello authors and team,

Can you please leave some feedback on our rejected Android App? What’s wrong with this

I got the email from envato market with the following comment: -

"Thank you for your submission. We have completed our review of “Affiliate Marketing System For Android” and unfortunately we found it isn’t at the quality standard required to move forward, and you won’t be able to re-submit this item again.

Here is the comment from your Envato Quality team reviewer:

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."

Demo:https://test.eracom.in/android/affiliatesystem/apk/app-debug.apk

Our many days of work has gone for nothing. We are really disappointed
Can you guys help us and tell us what is the problem with the UI of the app exactly. SO that we can improve that and repost the item.

Thanks