How to tell who is using my plugin

Hello –

Is there any way to find out which sites are using my plugin? I’m just curious how it renders across different themes. Of course I did testing on various themes prior to releasing the plugin, but you can never test them all.

Obviously a web crawler of some sort would accomplish this (assuming they’re not blocking crawlers via robots.txt), but if there’s something already out there that would be great.

Thanks!