NewsBlur.com-Notifier автор ThisUserNameWasAvailable

This extension will add a button to the toolbar, that shows the total count of unread news-items on newsblur.com, if the user is logged in. Clicking the button takes the user to newsblur.com (to /folder/everything, a specific folder can be specified instead). The button updates via the newsblur-api with a configurable update-interval. If a newsblur-tab is already opened, the buttons updates by parsing its title (Higher frequency, saves api-calls).

Based on the newsblur-notifier-extension for the old Opera-browser by Espen Helgedagsrud (kleevah@zawiarr.com) which was in turn based on "Google Reader Notifier" by al007. Had to pretty much rewrite it to make it work with firefox, though.