This add-on does not behave well on my Note 3. The toggle icon went away after I toggled off Java and I could not toggle it back on. I uninstalled and Java was still blocked, so i reinstalled it and found the toggle options in the drop down options in Firefox 57. I 'enabled' Java, but it was still being blocked. I finally had to uninstall Firefox and reinstall it to enable Java to run. Needs some further development before I could recommend.