Pretty good extension, does it's job pretty well. The only issues I've had with it are that you can't access the settings via about:addons, and that sometimes duplicate "check user" buttons appear. I would like to see the former fixed, since it's a little annoying to have to keep the extension in the toolbar overflow to access the settings. A fix for the latter would be nice, but it's mitigated by just reloading the page so I don't really care about it that much.