Tobii Dynavox Gaze Point is a software that allows you to move the mouse pointer and perform left mouse clicks. With Gaze Point you also get access to the settings, most importantly:
Turn the eye tracker on/off
Turn the visibility of the mouse cursor on/off
Turn left click on/off
Set the dwell time for mouse click
Gaze Point also gives you access to general eyetracker settings such as calibration, screen setup, etc.