How do I make a fullscreen mobile app?

I used crosswalk to export my app. When i run it, there are 2 part of the screen not used, letf one and right one, i mean the app run without the android status bar but it doesn't run in fullscreen. How can i make a fullscreen option? I was wondering if i have to change something in construct 2 programming part or in the settings before exporting.

Thanks.

Are you using the fullscreen setting "letterbox scale"? It is the default selected one on C2, and it creates black bars when the aspect ratio of the viewport does not match the aspect ratio of the window size propriety, if so, you might want to use scale inner or scale outer, but that implies to design your game accordingly.

What do you mean "design your game accordigngly" ?