Apple is switching on "iBeacons" across its 254 US stores today, according to a report from the Associated Press. iBeacons, which use low-power Bluetooth transmitters to offer location-aware services to your phone, were quietly introduced along with iOS 7, and although other retailers have toyed with the idea of adding beacons to its stores, Apple's rollout today represents the first major deployment of the technology.

The Apple Store iBeacons will work in tandem with the Apple Store app. Provided you've got the app on your phone and have given Apple permission to track you, it'll attempt to offer an augmented retail experience tailored to your needs. When you walk into the store and the app will enter "in-store mode." If you're standing next to an iPhone table you might receive a message asking if you'd like to upgrade your iPhone. If you like, the app will then check your upgrade eligibility and let you know how much you can trade in your old model for. Another example given involves notifications that will automatically bring up your order number as you walk up to a clerk to pick it up.

Apple iBeacons know exactly where you are

The AP reports that around 20 transmitters have been switched on at Apple's Fifth Avenue store in New York City, each adjusted to specific distances. Some of the transmitters are actual Bluetooth transmitters, while others are signals generated by iPads already installed at the store. Adjusting the strength of the signal allows Apple to show notifications relevant to exactly where you are standing. Such accuracy isn't easy with traditional location systems like GPS, especially indoors. It's not clear if the Apple Store application will require an update to display iBeacon information, but the transmitters are reportedly live in stores today.