I’ve looked into apps for half tone carving however everything is I’ve found is for Windows. I’m aware of setting up Boot Camp or Parallels, but I’d rather avoid that if possible!
List of options here: http://www.shapeoko.com/wiki/index.php/CAM#Images
Dmap2gcode should run on any platform which Python runs on: http://www.scorchworks.com/Dmap2gcode/dmap2gcode.html
With the help of a friend, I was able to open the app! Thanks