I had originally said "I cannot add this to Firefox ESR 52.4.1 (32-bit). I get the error 'this add-on could not be installed because it appears to be corrupt.'" I was able to find a solution at http://forums.mozillazine.org/viewtopic.php?p=14774300#p14774300: "
You will need to temporarily remove the config-prefs.js or autoconfig.js files to be able to install some add-ons (remove them with FX closed). Once the add-on is installed, put the file back to continue using the add-ons." I hope this helps someone.

Update: I've now used this for a few weeks, and so far, no complaints. After the initial installation issue, it was easy to use. I'll give it another month, and then will definitely make a contribution to support its further development. I should note that I had no problems installing it in Firefox ESR 52.4.1 (32-bit) on my workstation in my office.