NewScientistViewer.user.js

// ==UserScript==
// @name           NewScientistViewer
// @namespace      http://rampion.myopenid.com
// @description    (U) Hide "You have now viewed your 3 free articles" popover from New Scientist.
// @include        http://www.newscientist.com/article/*
// ==/UserScript==

// inject script, so hide overlay can use the has library, and runs after the popover happens.
const script = document.createElement('script');
script.type = "text/javascript";
script.innerHTML = "HaasExecuteActionHideOverlay()";
document.body.appendChild(script);