FF removes it from the toolbar. Rated 4 out of 5 stars
I've been using this for years and now (after FF update today, 5/6/14) FF keeps removing it from the addon bar (I added the extension to get the addon bar back). Still works great but I have to keep putting it back on addon bar. FF 29.0, Kubuntu 14.04.This user has a previous review of this add-on.