UPDATE:

After deleting the addon and adding it again, the addon seems to work great. No memory leaks at all.
I am updating my score to 5 stars

ORIGINAL:

It was working great some weeks ago. Now it's impossible to work with it.

Has huge memory leaks when I open it. Firefox ends taking all of my RAM (12 GB of my 16GB). My computer gets laggy and I have to close Firefox just 5 minutes after opening it.

I will disable the addon until this big issue gets fixed.

It was a great addon, but not anymore.