KGen retrieves every words of a page and lets you know how many time they appears and their weight in the page and their average position in the web page.
It give you some stats on the content of the page to allows you to improve your content quality. KGen's also a good tool to view your competitors keyword strategy.
You can get a CSV file of the scan to create an historic of your changes (web redactor clients will appreciate to get them to realize how your work increased their web page seo).
To open the KGen sidebar : View>Sidebar>KGen. You can also add the KGen button to your toolbars with the toolbar customization tool.
PS : KGen is pluggable with BBComposer allowing you to scan your content while editing it with your wysiwyg editor.