I am considering building a new plugin, which will connect to an Apple Iphone merchandising analytics tool, however I noticed that there isn't any clear way to see what sites have installed the plugin, so I can't whitelist them on the app.
Is there a way to see what websites have installed a plugin via the connect store?
If not, is there anything restricting me from putting something like Google analytics into the magento admin calls to my plugin to help me track usage and allow me to whitelist that way?
For your question number 1: NO
For number 2: There are many extension that "Call Home" You can also require that a user enter a license number to activate. Both methods will ensure that you track who is using it.