user interface - Testing Android App GUI -

I'm developing an Android app on GUI development, I have to raise the issue that if the GUI works on various Android phones So how can I test (I am with different screen sizes, density and etc.). How can I see that everything is right?

You are asking to do the hardest job in Android development

if If you are targeting the Motorola device, the SDK for the emulator is a bunch of adsense.

If you need to test a specific device, you can try to use it.