Firefox is one of the best modern browsers.
JDownloader is one of the best free download managers.
Flashgot is the addon for firefox that can integrate various download manager like JDownloader with Firefox.
Flashgot has the function to detect the download manager installed on the machine and it does support JDownloader.
In another way, JDownloader supports installation of Flashgot in Firefox and integration of them with JDownloader by providing a button.
But JDownloader’s button to do so does not work (in my case) with later Firefoxes.
I carried out the following procedure to integrate Flashgot with JDownloader.