Steve Kohn gave us a heads up about MagicPlan, a mobile app that allows you to create
floor plans using your IPhone, Android or other supported device. As near as I can
tell, there is no Windows Phone version available.
The MagicPlan website explains the details, but essentially, you take a bunch of
pictures of the room or site, and the app uses these to create a floor plan in JPG
format. This can then be used in PartyCAD to make a ‘Picture as Plan’ style project.