Rated 4 out of 5 stars

yazan: Peja_Stija-42 tarih: Ağu. 6, 2017 ·

Works fine in all FF except version v57.

This review is for a previous version of the add-on (1.08). 

yazan: magicp (Geliştirici) tarih: Eyl. 3, 2017 ·

Sure, It's not compatible with Firefox 57. Please check version information.