How to make a .png file for Muvizu using GIMP. I used GIMP for this, as it's free, but you can use the same technique in most image editing software. http://www.gimp.org
This was a hints & tips video made with a slightly older version of Muvizu. http://www.muvizu.com

The image for the window was made using a screenshot from the app.
You can access it here:

http://i.imgur.com/IN2yr.png