Apple Inc. ’s upcoming iPhone map application will include Yelp Inc.'s “check-in” feature to let users broadcast their whereabouts to friends, according to materials Apple distributed to software developers.

Apple Maps, which will replace Google Inc. as the default location service in software set to debut later this year, will allow users to communicate through Yelp without exiting the map and opening a new app, the materials show.

Yelp, a website that lets users review businesses ranging from plumbers to pet shops, introduced a check-in service for mobile phones in 2010 in an effort to help local merchants build loyalty with regular customers. Integration with Apple Maps may help Yelp challenge Foursquare Labs Inc. and Facebook Inc. (FB), two leading providers of check-in services.

The Apple developer kit, which was given to programmers earlier this month and examined by Bloomberg, includes screen shots of Yelp check-ins within Apple Maps. Trudy Muller, a spokeswoman for Cupertino, California-based Apple, declined to comment, as did Vince Sollitto, a spokesman for San Francisco- based Yelp.

Mobile check-ins use the GPS capability in smartphones to let users share what local businesses or events they’re visiting. The feature can show how many other people have checked in at a location, whether those individuals are friends, and can publish users’ whereabouts through social-networking services such as those operated by Facebook and Twitter Inc.

Yelp is ramping efforts to attract local advertising, which made up 70 percent of revenue in 2011. Check-ins are used by 18 percent of adult smartphone owners, the Pew Research Center found earlier this year.

Apple’s iPhone has featured Google Maps since 2007, when the earliest version of the devices went on sale. The next software update, called iOS 6, will be the first one to include maps developed by Apple.

Source: Bloomberg