The second one I've got is the graphing calculator. It lets you input up to 5 different equations and also graphs them:
The third add-on I've been able to find is the facebook messenger. It let's you talk to your friends on facebook, but without leaving the window. It show to the right of your current window.
The next one I found is the photoshop tool. It lets you photoshop pics from the internet. We are using photoshop in Photo Imaging to mess with different picture we take around the school.
Another one i've had the honor of finding is the Start Free Games add-on. It let's you play a lot of the older games that you grew up as a child. I was jumping up and down with joy when I found this one:
Another add-on I found was the google translator. It lets you translate different languages into others:
Hope you guys find this useful! There's a lot of other add-ons that i didn't include, so make sure you try them out! Have a wonderful day! :]