The Edge Notifier for Chrome is an extension that pops up a notification when there are new posts available on the forum like so:
Somewhere around Chrome version 33/34 Google has decided not to allow you to run extensions that don't pay to use their webstore. To get round this either use Chromium or follow these steps to install the extension:
When the extension first loads it will report that there are a lot of new posts. Don't panic! This is because the extension is experiencing the Juggling Edge for the first time and thinks that everything is new. The next time it checks for new posts it will be a little older and a little wiser.
If you have any problems please post on Meta talk.
15th Oct 2013 - Version 1.1
14th Oct 2013 - Version 1.0