I would rate 5 stars, but updates to the Firefox extension don't keep up with those to the Chrome extension. For example, Proton Pass introduced custom item types a while back, and within like a day, all their clients (mac, linux, chrome extension, etc) rolled out an updated version that supports them. Well, all except for the Firefox extension. Thus, custom item types can't even be seen - much less used - within Firefox. Otherwise this is a great extension with a pleasant UI.