Unusable on GNU/Linux Ubuntu 18.04, FF 61.0.2 (64 bit): the addon window won't stay open, it will collapse before even typing a single letter inside it.
The support site does not seem to work either (404, page not found).
Thank you for the effort, but the code needs a thorough rework.
This has been fixed/does not occur anymore on new Ubuntu releases. I have updated this to the master branch version so it isn't just an old Firefox port. Support page fixed and now links to GitHub.
