code: function enterFullScreen() {
      if (Windows.UI.ViewManagement.ApplicationViewBoundsMode) { // else crash on 8.1
          var view = Windows.UI.ViewManagement.ApplicationView.getForCurrentView();
          view.setDesiredBoundsMode(Windows.UI.ViewManagement.ApplicationViewBoundsMode.useCoreWindow);
          view.suppressSystemOverlays = true;
      }
  }
docs: Enter fullscreen mode