SD Tools requires that you accept the following End-User License Agreement before installation can proceed:
SD Tools - a Firefox extension for management of links to files hosted on popular file sharing and hosting sites
Copyright (C) 2011-2013 Mario Ljubicic - sharedir.com
This program is free software; you can redistribute it freely and modify according to your own purposes, however, a distribution of such modified version is NOT permitted.
This program is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.