Apple Inc., whose mapping software has been criticized for misguided directions and inaccurate landmark, bought startup WiFiSLAM to add location-identifying technology for when a user is inside a building. 

"Apple acquires smaller technology companies from time to time, and we generally do not discuss our purpose or plans," said Steve Dowling, a spokesman for Apple, confirming the deal.

advertisement | advertise on newsday

The purchase is among several Apple has made in recent years to improve its navigation capabilities as it competes with Google Inc. Last year, Cupertino, Calif.-based Apple introduced its own mapping software to replace Google's, a switch that resulted in user complaints and negative reviews. Apple Chief Executive Officer Tim Cook apologized and vowed to improve the service. 

WiFiSLAM, based in Palo Alto, Calif., is part of a group of companies helping users find a location when they are inside a building like a grocery store or shopping mall. Google also has been creating maps for indoor locations like museums.

The acquisition was first reported by the Wall Street Journal, which said Apple paid about $20 million for WiFiSLAM.