BT/Magnet link addon
https://addons.mozilla.org/en-GB/firefox/addon/magnet-linker/?src=search
https://addons.mozilla.org/en-GB/firefox/addon/torrent-to-web/?src=search
https://addons.mozilla.org/en-GB/firefox/addon/torrent-control/?src=search
https://addons.mozilla.org/en-GB/firefox/addon/magnet-link-to-transmission/?src=search
https://addons.mozilla.org/en-GB/firefox/addon/transmission-easy-client/?src=search