Document Studio for Google Docs - Easily perform mail merges with Google Docs

Web Address:  https://chrome.google.com/webstore/detail/document-studio/nhgeilcelhkmajkfgmgldbinmgjjajlb

In their own words:  "Create documents with Google Sheets and Google Forms responses. Includes Mail Merge, Store merged files in Google Drive and ShareCreate documents from your spreadsheet data and Google Forms responses in a snap."