Android Supporting Multiple Screens

[Redan Hassoun]

Hi,
I have developed an android application, now i want to test this application for different phones, because different phones have different screen sizes.
I have installed GenyMotion , and also installed Google Play Services in it.
This is the first time i do this kind of tests , so i want to learn from you big guys what is the convention to do this testing for multiple screens, in other words , how android experts do this ? ?