Google Doc Publisher - Make Google Docs good-looking in two clicks
Publish to WordPress - Publish content on WordPress right from Google Docs
Content Editor 2.0 by Surfer - Content Editor is the most advanced content optimization tool that allows you to write and grade your work.
Dimer Beta - Simplest way to write and publish beautiful docs
SEO Minion - Chrome extension & Firefox add-on to help you with SEO
SEO Tool Extension - Your favorite SEO tools, placed for quick access.