Ask HN: How to build user experience for mobile applications

I am developer more specifically a back end coder but when it comes to developing front-end for user i am not very well in it. I have develop a android app in my spare time which let user

1- Location based search on Google map

2- subscribe for live tweets on a particular location ( also send tweets analytic i.e. no of tweets, top tweeter )

3- Sign in/ Sign out/settings and other about us tabs

I have completed the functionality but looks very simple because of front end. Is there any guide or tips available about How to create user experience in your app which keeps user interest in it. when i use apps develop by GOOGLE, APPLE and big giants they looks completely different, every layout, button and everything used make perfect sense

ANY TIP HOW TO MAKE APP MORE USER FRIENDLY Thanks