Q. At the academic writing workshop, they showed us a resource that listed a lot of words for academic writing, what was it?

You're thinking of the Academic Phrase Bank, provided by the University of Manchester. You can get to it from the page on Academic Language of the Writing Guide, under the Writing Process tab, but here's the direct link:

http://www.phrasebank.manchester.ac.uk/

It's a handy little thing, that can help you shake up your sentences while still sounding "academic".