Be careful. I purchased the extension linked to above (which, to be clear, is NOT a Webassist extension) and it shipped with an invalid ID and password, rendering installation impossible. The auto "forgot password" button offered at the failure point did not result in further instructions and an email to support from yesterday has, thus far, gone unanswered.
I requested a refund through PayPal which was immediately provided without comment. Something doesn't seem right.
UPDATE: Since other links have been provided, I feel it necessary to make clear that the extension to which I am referring is the one from DMXZone.