IMAGE_CTRL DMG Canvas is amazing. I'm surprised the developer is offering it for free (with $15 donation suggestion) since it's stronger and more user friendly than any of the other paid apps.
however, i did find a problem with the app, which i don't hold against the developer because it's freeware, and because i'm sure it will be sorted eventually. the problem is with the "Internet Enabled" option. if this option is unchecked, it works as it should locally and does not automatically copy contents of the DMG into the downloads folder. however, when the same .DMG is placed on a server and downloaded with Safari, it will copy contents automatically.
(Version 1.0.2)