HNProfile is a free Chrome add-on developed by Pleasant.io. It falls under the category of Browsers and specifically the subcategory of Add-ons & Tools. With HNProfile, users can add profile overlays to Hacker News usernames, allowing for a quick glance at a user's profile without leaving the page they're on.

This handy tool provides users with information such as a user's bio, karma, and account age. It also offers quick links to their comments and submissions. Additionally, if a user has an email address or Github account in their bio, and they have set up a Gravatar or Github avatar, HNProfile will display their avatar as well.