#1 Too Many Tabs
Summary: This extension is for the tab hoarders out there. It allows you to see a visual of all of your open tabs. It also allows you to easily suspend the tabs that you are not currently using so you can improve your computer's memory. When you need to access the suspended tab, simply open the extension and move the suspended tab back over.
#2 Notifier for Twitter
Type: Social & Communication
Summary: This extension displays tweets, mentions and/or direct messages as pop-ups on your computer screen. It will also pull up your Twitter feed in a pop-up window so you can quickly check tweets from any open tab/window. I personally choose to just be notified when there are mentions or direct messages because I would never get anything done if my twitter feed was popping up all day.
#3 English Dictionary Translate Pronunciation
Type: Social & Communication (but I consider it more productivity)
Summary: Use this extension to have a word pronounced for you. Also shows the definition of the word and gives you the ability to translate the English word into another language. Great extension for the English language learners.
#4 Explain and Send Screenshots
Summary: I take a lot of screenshots to send to people in order to explain something. This extension is great because I can quickly take a screenshot and then annotate on it. I can download the image or share the link to the annotated screenshot.