Google has been trying to give a push to the social networking tool with new features like private message. Now Google has released the official notification extension for Google Chrome. With the extension installed, you can view all the account notifications without having to open Google+.
You can click on the notification button available on the toolbar. The toolbar shows the count of unread notification available. Although this feature is available across all Google apps using the new Google toolbar, this is helpful only for people using Google Crome. Notifications include updates on who added you on Google+ and who added a comment or +1 to one of your posts or a post you commented on.
Clicking on any notification will show you the post just like the way it shows in Google+ and clicking on any link opens the post in Google+.