Apple has bought indoor-mapping specialist Wifislam as it looks to expand its maps product to compete with Google. Google’s service also draws data from nearby wifi hotspots and signal towers to pinpoint location in a way which is more accurate than satellite positioning. Wifislam’s technology works by using smartphones to “pinpoint its location (and the location of your friends) in real-time to 2.5m accuracy using only ambient WiFi signals that are already present in buildings”. http://www.bbc.co.uk/news/technology-21924240