Rated 5 out of 5 stars

Version 5.5.3 was removed from site. I maked a copy of the add-on.
For Windows x64. Just decompress and put into C:\Users\youruser\AppData\Roaming\Mozilla\Firefox\Profiles\????.default\extensions

https://mega.co.nz/#!YRVQEYiD!DAW-KBgRrW5FxWHayFyhu-p9KrXi0rw6nxApKzgr5lc

Greetings

This review is for a previous version of the add-on (5.5.1.1-signed). 

Version 5.5.3 can be found here:

https://cys.mantishub.com/view.php?id=1

A new version should be ready soon...thanks for the 5 stars!