Just click the tota11y icon to run tota11y from Khan Academy and visualize how your site performs with assistive technologies.
tota11y was just released by Khan Academy and was available as a bookmarklet. It seemed natural to create a Chrome extension. So here it is. All this does is inject the tota11y script onto the page.
See tota11y's website for information how to use it: http://khan.github.io/tota11y/
The source code is available on https://github.com/kvasir/tota11y-chrome and was made with love by John-Philip Johansson and Michael Strömberg Razmgah.