http://eoscount.com
now fully supports EOS 6D, EOS 70D, and all the latest EOS cameras on both Windows and Mac. The Windows version now also supports Windows 8.0 and 8.1.
A reminder: EOSCount, unlike some other programs that pop up, uses Canon SDK to retrieve a shutter count from a camera. This is the same method that Canon uses in their technical centers and is the most trustworthy. Just because a program gives you a number and labels it "shutter count" it does not mean it is accurate. Even if a program not using Canon's method is accurate in some instances, it cannot be relied on to be accurate 100% of the time.
Caveat emptor: you get what you pay for.