Fanfiction & AO3 Filter от πRia

This add-on lets you hide stories from FanFiction.net and ArchiveOfOurOwn.org that have fewer Reviews, Favs, Follows, Kudos, Bookmarks, or Hits than your chosen threshold.
Since I don't have access to their full databases, the add-on doesn't search all stories—it only checks the ones on the current page and hides those that fall below the specified stats.
This can be especially useful if you're like me and sort stories by date posted. You won't have to slog through pages of low-quality content just to find the few good and popular ones.