Does anyone have experience with the Shutter Check (for Mac) $10 software for determining the shutter count for the 5DIII and 5DIV? I don't mind spending $10 if it works and doesn't contain malware. I found a site "CameraShutterCount.com" that claims to be able to calculate the shutter count from an uploaded image, but I'm leery of trying this and don't see how it could possibly work given the first 4 characters of the file names repeat after 9999 images. As my cameras are set to continuous for file naming, I manually went through my picture folders for my 5DIII to determine how many cycles occurred and came up with a count of about 22,000. However. I'd like to verify it for purposes of a sale.