Shows the outline of images obtained by the camera.
Press the screen to activate the camera flash in torch mode, thus improving the recognition in very dark places. Press the options key on your device to open the menu of resolutions and line thickness. Select one of the resolutions supported by your device camera (lower resolutions work faster), and one of the five line widths available.
This is just a tool, not a permanent solution! Do not dismiss the utmost care, or a friendly help, to move in dark environments!