So there’s a similar Chrome extension for Reddit called Reddit Pro Tools. What it does is add little visual indicators about posters and sources on Reddit. It analyzes the posting history of a user and if they have a lot of upvotes from a couple of subreddits (conservatives, the_donald, kotakuinaction, etc.) it puts a little indicator next to their username to warn you of that.
Hovering over the indicator provides more information.
It does this everywhere on Reddit. It will also put an indicator if the user is a new account. It also flags a post that links to a list of mostly conservatives sources, like foxnews, as “propaganda.”
I find it very useful, but I also find myself automatically downvoting comments and posts by people who are flagged in such a way. I suppose this says more about me than it does for the extension, though.