RoomScan is an app that easily draws floor plans by itself, so you never have to bust out the measuring tape and get down on your knees. All you have to do is touch each wall with your phone, and the app goes about gathering the dimensions and putting together an approximate floor plan that takes into account the length and heights of walls and floor area.
Measurements are estimated to the nearest 10 cm (or half a foot if you decide to choose feet as the measuring index). Measurements can be made in metric, feet & inches and even obscure East Asian measuring units.
Roomscan can easily draw floor plans of rooms of different shapes including L-shaped and more complex rooms, as well as regular square-shaped and rectangular rooms.