The company demonstrated the technology to The Associated Press this week at its busy, 24-hour Fifth Avenue store in New York City. At this particular store, Apple has installed about 20 iBeacon transmitters, some of which are simply iPhones and iPads, which come with the capability as part of the iOS 7 mobile software released in September. The transmitters use Bluetooth wireless technology to sense your exact location. That's not possible with GPS, which don't work well indoors and aren't good at distinguishing between locations that are just a few feet apart.
Once you enter an Apple Store, the app will automatically switch to "in-store mode". If you enable In-Store Notifications, the app might notify you if your computer is ready to be picked up. When walking past an iPhone table, the app might ask if you want to upgrade, check your upgrade eligibility, or see if you can get money for trading in your old device. Depending on where you are standing, you might also get notifications about deals or upcoming events.
You can download the Apple Store app from the App Store for free.