Mac OS X 10.8 (Mountain Lion) and HIGHER Users:

A new feature of OS X Mountain Lion, and higher versions of OS X may block software installation if the software is not signed by Apple.  To install the LexDye Definition Tracker software you will need to change your settings to allow the installation of unsigned software.

Before trying to run the software, enable the installation of Applications from "anywhere" by going to:  System Preferences –> Security & Privacy –> General tab: