Next time just wait a little for an answer. In the emulation windows on the right side click Device and network setting there is a toggle to Show status bar unclick it. Note what you looking at is only an emulation on most devices the bar is hidden also changing this setting does not changed your project just the xdk emulation setting
No, you did not understand me. I asked how to make full screen in the application, without the black bars using intel XDK. In C2 chose a resolution of 1280x720 and Letterbox scale. But on different smartphones are black bars top and bottom or left and right.