How to send data from an Arduino GSM Shield to Android devices?

Hi there!

I am currently working on a project, which is about sending data from arduino to smartphones. (android)

I have very small knowledge of networking. I also don't know php and sql.
I have a decent understanding of arduino, java, and android.

The task is simply to send some integers through for example a web server to android devices, no more.
I want to accomplish the task with GSM Shield because of its flexibility.

How could i aproach this project?
What is essential to know to get started with it?

Also, i would like to get done with the project as simply as possible, due to the lack of time.

Thanks for your help!