RoomScan is a free app that can expedite floor plan drawings for existing infrastructure. It’s particularly useful for home projects where you might need to know an approximate square footage for carpeting, painting, or furniture arrangements. The app works quite simply. Once the app is installed, you can start adding floor plans to your app by holding the phone against each wall. If you pay for the pro addition ($4.99), you can add a door opening as you go. The pro version also comes with an option to use a laser scanner for better accuracy. Currently, there’s no export option, which makes it difficult for professional use by planners, designers, and draftsmen.