Does not works on... Rated 3 out of 5 stars
The counter does not shows up on toolbar (ffx 3.6).
The last version that works also on firefox 3.6 is v1.9.3.
Developer should test the extension on all versions of
firefox he claims it works on..
Otherwise, should drop the support for older versions, except
of firefox 3.6 which is still in use by many people.