Rated 5 out of 5 stars

Really makes reading the lengthier ars articles great. Seems to be broken as of 10/3/16 in Seamonkey 2.40.
Error console gives this:
Timestamp: 10/3/16, 12:01:18 PM
Error: pageNumbersIndexNode is undefined
Source File: resource://gre/modules/addons/XPIProvider.jsm -> ... > resource://{952f9f9b-23b6-4ab7-ac65-0dd218dbabd8}/content/ArsTechnicaSinglePage.js
Line: 99

This review is for a previous version of the add-on (3.1-signed).