Box It

A simple google doc add-on allows you to add a gray box with or without selected text.

How to use

1. open a document in google doc
2. select the text you want to add box with
3. find "Box It" in the Add-ons menu
4. click "Add Box" and voila!

Note: if you want to start without a text box, you can add it anywhere you want by simply click on the same "Add Box" button