Associated Press reports that Apple stores are now using iBeacons to provide precise location information as you walk around different parts of the store.

On Friday, Apple Inc. began using the technology at its 254 U.S. stores to send you messages about products, events and other information — tailored to where you are inside, provided you have downloaded the Apple Store app and have given it permission to send notices based on your location. You must have Bluetooth turned on and have the latest operating system, iOS 7.

Using the iBeacon feature, the app will notify you if the computer you ordered is ready for pickup, for example. Show a clerk your screen with the order number, and the clerk will get it for you. Walking by an iPhone table? You may get a message asking if you want to upgrade, check your upgrade availability and see if you can get money for trading in your old phone.