ok my favorite app so far is Surplus which just updated to version 3.
one of our fellow chrome pilots anitmatter 15 did an awesome job on this one that basically shows us the google+ notifications as an extension so we can get updates when we aren't on a google app page... it's sweet and it keeps getting better. if you love google+ you will love this chrome extension.
so in the pic do you see the red square with a white 2 in it? that's the extension. I have two updates.. when I click on it a drop down menu shows with the notifications... very well designed. hint, you may have to click on the pic to make it large enough to see what I am talking about
here's his description of the update:
Surplus3 has now been released. It has now switched from Google Video to Google Images as the page host, so that should evade some corporate firewalls. It automatically adds the current page's link to the area when sharing posts. The popup should be much more stable and some other backend work. Also, clicking on the button again should close the box.