I think we agree that the Aquarium should check periodically to see if it is the latest version. I would just have the Aquarium do the "heavy lifting" of doing the version comparison rather than the website.
If the Aquarium just downloads
http://www.serenescreen.com/VERSION then anyone can download it and confirm that there is no hinky business going on. The
suspicious people can't really complain.
If on the other hand, the Aquarium is calling
http://www.serenescreen.com/version.php?ver=30100 then the website could be tracking information about what versions people are running. I'm sure those folks who get suspicious will point to this as "bad behavior" by the Aquarium.
I admit it WOULD be nice to know what versions people are running though.