Fix PHP-Android problem on loading data error

Avg Bid (USD)
Project Budget (USD)
$250 - $750

Project Description:
I am looking for some people to help me fix some problems and develop more functions of my app.
This is my app link on Google Play:

I want to get a real developer who can fix my bugs.
So please install app and understand clearly my bug before bid.

Problem: get null point when click "load more data" to end of book.
P/S: I need a long term contract. If you qualify this problem, I will hire you to help me develop many functions on my app.

* When you bid please comment your solution. I don't want to hear something like "I can do it well"
If your solution is good, I will hire and give chance to work long-term contract of our projects.

Skills required:
Android, Internet Marketing, Java, PHP, Software Testing
About the employer:
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