I use Qbserve, can vouch for it being a very nice tracking system. Can't vouch about its privacy guarantees, but only because I haven't double-checked them. (I use Qbserve only on my work computer on which I don't plan on doing anything I wouldn't my employer to know). It does have some kind of database in which URLs/programs have a crowdsourced taxonomy. For example, I think news.ycombinator.com is by default flagged as "Distracting" activity. For sites/programs that haven't been classified as "Productive" or "Distracting", things are put into a "Neutral/Uncategorized" bucket. And you can go into the details panel and manually classify the content for yourself.

When doing the classification, there is a checkbox for "Send to developers to improve Qbserve": https://imgur.com/a/Rei0e

I have no reason to assume that that checkbox is obeyed, or that info isn't leaked in other ways -- but just saying I haven't tried to verify it FWIW.

There was a front-page Show HN from Qbserve 2 years ago: https://news.ycombinator.com/item?id=11778077