If you're not entirely fond of the WYSIWIG layout creator and prefer to do things with code, use the following snippet to make the app full screen.
public class SlowPokeActivity extends Activity {
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
// Make it completely full screen
this.requestWindowFeature(Window.FEATURE_NO_TITLE);
this.getWindow().setFlags(WindowManager.LayoutParams.FLAG_FULLSCREEN, WindowManager.LayoutParams.FLAG_FULLSCREEN);
}
}