Why to add this addon anymore? I discover Firefox added default zoom in version 73! It is under Options, General, Zoom. This was big problem before because Firefox can remember and save after changing site but always started with the 100%. But since v73 you can change starting level to something other 100%. Maybe some very special zoom mode exists with this addon but I think for most user there is no reason anymore. I use zoom addons for long time like No Squint because it was necessary, now I don't think so. Also I have some doubts about the permissions. Why zoom needs to access all data like password entered on site.