To address your concern with the privacy, WhatRuns do not collect or log any visitor information including IP address, location etc.
We receive anonymous website data and match with our database to display the results. Hope this clarifies.
That's not the whole truth - you are using Google Analytics to track visitors and you fail to disclose this in your privacy policy, despite this being mandatory under the Google Analytics T&C's.
Well done launching what looks like a very cool project, and I hope you can further improve it by informing visitors that you are using Google Analytics to track them (or even drop GA completely in favor of something privacy friendly).
Good luck with your thing. I am sure you did a ton of work; I am just naturally risk-adverse when it comes to installing extensions that that a potential to do things I might not want.