WriQ is a Google Docs add-on that you get from the Chrome Web Store. Here’s the link:
Once you add WriQ you’ll be asked to grant some security permissions, as is usual with any Docs Add-on:
When you have installed the add-on, it’s available in the Add-ons menu of any Google Doc that you have opened. Just click the WriQ menu, and choose Show WriQ.
For information about using WriQ please read Getting started with WriQ