<p>An invisible control may be implemented in a client device or in an application of the client device. A user may activate the invisible control by applying a gesture on a predetermined region of the client device or the application. In response to receiving the user gesture, a predetermined action associated with the invisible control may be activated. The predetermined action may be applied to the application or some or all of the content associated with the application. An Application Programming Interface may further be provided to allow the user, an application vendor or a content provider to customize the invisible control or operating modes associated with activation of the invisible control.</p>
