You could have downloaded SmartNav 2.7.3 for Mac from our application library for free. The actual developer of this free Mac application is RJ Cooper.
From the developer:
SmartNav is an app that allows you to control the mouse cursor with your head. The configuration menu lets you set the Dwell Click time interval from 0.2 to 2 seconds for maximum control and comfort. The Dwell Clicking feature is fully compatible with all virtual keyboards and other Windows based accessibility programs for people with disabilities.
Drivers