Looking for an add-on

I used to have a great Firefox add-on that let me right-click on an LJ (or DW) entry and expand all the comments, but it mysteriously disappeared last time Firefox updated itself, and I can't remember what the danged thing was called so I can't find it again to reinstall. Do any of you know what I am talking about and remember the name of the add-on? I used it ALL the time and I miss it a lot.