What if NetSpot OSX would allow getting data from an Airport Express (configured as wireless repeater), which you could stick in various mains outlets around the house.
Even better, if the Airport Express would be plugged into a long mains extension cord, then we could take the Airport Express for a walk, while the NetSpot OSX app would be scanning.
If necessary, there might be an Airport Express configuration which is best suited to make it serve as a slave WiFi scanner.
