Tap on the camera tile that you want to view and enter the Live View camera screen. If the Live View tool icons are not showing, tap anywhere on the screen to bring them up. Tap the Record icon in the bottom tool bar. Selecting this button will have the camera start recording. To stop the recording, tap the button again, or it will stop on its own when complete (default video length is 20 seconds). You can then view the recording in your Activity list.