Can you pl. give me the access to your 'test server' where I can test my application ?
I'm not Erel, but I give you the answer: Noone will give you access to his/her webspace!
I tried to register on a site offering 'free website hosting', completed the formalities and got access to the site. I created the MYSQL database etc. and also uploaded your PHP script. But they are saying that 'they do not offer any interaction with mobile devices in the free version'.
So why don't you ask how you can solve this?
By the way 5-10$/month for a reliable webspace is not too much.
Solution (not that safe - only for testing!)
1. Download and install XAMPP
2. Open a port on your router and route it to the machine where XAMPP runs (e.g. 192.168.1.22)
3. Your php script must be under /htdocs and use correct credentials to connect to MySQL
4. Get your Internet address which you are connected with (your router knows it). This is not static if you haven't one in your plan.
5. In your app call this address using OkHttpUtils
If you have questions how to do this or that: Use the forum search AND the WWW (as this is not B4x related).