This extension is absolutely indispensable in the toolbox of every web designer / frontend developer. But..
With the restrictions of the latest 'updates' of Firefox the workflow of this awesome add-on is completely DESTROYED

It's like forcing the dentist to drill teeth with a rake..
My advice:
1. Download the last working version -whit this add-on- of Firefox (be sure to disable automatic updates!)
- http://ftp.mozilla.org/pub/firefox/releases/56.0.2/win64/nl/

2.Install the one and only working version of this fantastic add-on (Version 1.2.13)
-https://addons.mozilla.org/nl/firefox/addon/web-developer/versions/


Can someone give me advice about a software package / IDE that offers the same functionalities (and front-end workflow!!) of this add-on?