Another option for driving your TinyG CNC seems to have been released recently (it also supports grbl too)
Check it out here:
http://www.jtronics.de/software/jcnc-cnc-steuerung.html
I have not tested other than running opening it up.. running a file though it. It seems to have worked in the preview. However I have not tried to mill with this program as of yet.
I ran build 380.08 on my TinyG when testing out the program.
riley