If you have notifications to read, then most of the websites will add a number to the tab name. Tab Badge is a Firefox extension that lets you see which tabs are calling for your attention with a red badge. It displays a red notification badge to alert a user when he/she receives a message across websites such as Facebook, Twitter, Gmail, etc.
For pinned tabs, the badge is also displayed. This way the utility instantly gets alerted when a new notification is received. Suppose you have 5 Facebook notifications, the display badge will be Facebook (5). This helps you not to repeatedly check numerous tabs for new messages and notifications across email addresses and social networking websites.
The sad part about this extension is that it doesn’t provide any options to disable the badge alert for specific websites. But it instantly alert users to check the tab with notification. Tab Badge works with Firefox 4.0b7 – 4.0. It is available as a free download from the below link.