Apple has paid US$20 million to buy WifiSLAM, a company that develops ways for mobile apps to identify a user’s whereabouts in a building using Wi-Fi signals, reports “The Wall Street Journal” (http://tinyurl.com/antm4gf).

An Apple spokesman confirmed the deal, telling the “WSJ” that the company “buys smaller technology companies from time to time” and generally doesn’t discuss its plans. He declined to comment further. WifiSLAM could not immediately be reached for comment.