Resource:
http://kgen.elitwork.com/
Description (from site):
"KGen allows you to get the most important keywords of a webpage. It's really usefull to analyze the SEO strategy of your competitors or simply know what's the main subject of a webpage."
Download the plugin from:
http://kgen.elitwork.com/download/kgen.xpi
Tutorial/How to use the plugin:
http://kgen.elitwork.com/manual.html
Uses: Helps with content strategy on your blog, keywords to target and theme clusters to create, backlink building strategy, etc.