It's only redirecting to their online page and the're unfortunately only too few functions that are not already built-in Firefox. only adding image to pdf and I dont like workspace: cant even zoom the file.

Didn't load the PDF at all. Does not react to a PDF web address.

This add-on takes you to a cloud based editor, as you do not know the provider it would not be a good idea to fill in forms that contain large amounts of personal information, such as bank details or tax codes.

For general stuff it's an OK solution, but you need to enable ads to allow it to work.

I imagined that the extension would allow me to edit the PDF at the URL that's in the browser.

Instead, the extension seems to be primarily a link to http://www.redcoolmedia.net/onlineeditor/preloginpdfoffice.html

Maybe a great service (I didn't test it) but version 1.3.5 of the extension seems to do little more than can be done with a simple, traditional bookmark.