Productify - Sell your WordPress content using Gumroad
Google Doc Publisher - Make Google Docs good-looking in two clicks
Additor beta - Pocket and Evernote got a minimal and collaborative baby
Content Editor 2.0 by Surfer - Content Editor is the most advanced content optimization tool that allows you to write and grade your work.
Typeboost - Music stops when you stop typing. Stay focused while writing
SEO Minion - Chrome extension & Firefox add-on to help you with SEO