I got YoWindow 4 from Windows Deal. The deal has expired. But the form for a free license key comes up in Google and I just got the email with the license key(I applied with another email address just to see if they would honor the request. They did.) It says YoWindow unlimited 3
but maybe nobody updated the form letter. ( edit: I just checked the license I got for 4 and it says 3 so you should be good.. maybe.)
Anyway you could try the license key they send you with a download from Softpedia and see if it registers.
Here is the form url to apply for the license:http://yowindow.com/...for_windowsdeal.php#
It would be better if it was actual video from a weather cam(or even a still every 20 seconds or so) rather than a simulation. But what is kind of fun is you can crop your own photo and have the sky in motion as background. Here is one I did using a picture of Miami.