Rated 4 out of 5 stars

you can use small hack to bypass version check

download refspoof_0_9_1.xpi to your PC and rename it to refspoof_0_9_1.zip

open zip archive a locate install.rdf file

now, you must edit it with text editor
(attention install.rdf has linux style end of lines)

locate 3.0a2
and change it to

rename zip archive back to refspoof_0_9_1.xpi
and drag it into Firefox window and install it

This review is for a previous version of the add-on (0.9.1).