“In this article I will show how to build PHP XML RPC server and how to consume provided services with PHP and an Android application as a client. […]” “http://www.codeforest.net/how-to-build-php-xml-rpc-server-client-and-android-app

“Android runs on a variety of devices that offer different screen sizes and densities. For applications, the Android system provides a consistent development environment across devices and handles most of the work to adjust each application’s user interface to the screen on which it is displayed. At the same time, the system provides APIs that allow you to control your application’s UI for specific screen sizes and densities, in order to optimize your UI design for different screen configurations. For example, you might want a UI for tablets that’s different from the UI for handsets.[…]”

http://developer.android.com/guide/practices/screens_support.html

How to change pixels in a bitmap:

http://stackoverflow.com/questions/1309629/how-to-change-colors-of-a-drawable-in-android