Add this to any page, and you're golden: (See the demo!)
<script src="//fightforthefuture.github.io/reset-the-net-widget/widget/rtn.js" async></script>
The widget is designed to only appear on June 5 2014, and only once, per user, per device. If you'd like to force it to show up on your page for testing, please (re)load the page with #ALWAYS_SHOW_RTN_WIDGET in the URL.
(eg: http://flagger.io/#ALWAYS_SHOW_RTN_WIDGET)
Modern browsers, and the two latest versions of Internet Explorer.