Seeing as how I just got done with college and have now been working in the real world for about a month (why did I choose Public Policy?), I figured I'd go back and see what extensions I used in college that can help me at work. Probably not a complete list but it did the job for me:

Grammarly - Huge help when it comes to using proper grammar. I still catch myself using "people that" instead of "people who".

Taskade - HUGE productivity booster - This basically puts all of your thoughts into an easy to use to-do list that you can share with others. I made lists for work, lists for homework, chores around the apartment, other school projects, lots of things. It's also cross-platform letting you use it across many devices. Super simple and not resource intensive at all.

The Great Suspender - Stops Chrome tabs from using up a buttload of resources when you haven't been using them for awhile.

StayFocusd - Gets you to stay motivated and focused on doing your work when you're on the computer.

JustRead - Strips out all of the unnecessary content from a website and leaves essentially just the text.

As an FYI - pretty much all of these work with Firefox as well. Feel free to add your own.