Good for quick estimate-

Used this app to get a shutter count on my Canon T3i prior to sale. App was unable to see the camera until I installed Canon’s EOS utility on my MBP. Based on my usage I think the count is reasonably accurate. From what I’ve read it’s difficult to get an exact number, and with shutters rated to 100k+ actuations, ballpark is good enough.

Elevated.tv about ShutterCount