Well, I Love this. Using my flic to control my Mac is just AWMPGHDFHGIFDGHIDF... SO MUCH WIN!
So feel free to re-use this. I have searched a little bit over the internet to create an script that mutes my Mac when I press my Flic. Here is the code:
set _muted to (get (output muted of (get volume settings)))
if _muted is false then
set volume with output muted
set volume without output muted
Just paste it into a "script.AppleScript" file, and give it execute permissions > $ chmod +x script.AppleScript
And it will be ready for you to use with the app!
Cheers and keep doing great things!