Since iOS8, when near to the beacon, system is showing an icon of the app that is using this beacon in left bottom corner on a locked screen. I have seen screenshots on the web that are showing shopping card icon when user doesn't have the app installed. I wonder how does iOS identify the app basing on beacon? Do developer have to register his beacons somewhere?
Those icons are for apps that are already installed on the phone (the screenshots show the AppStore app and the Apple Store app). The icons show up on the lock screen whenever the apps discover a beacon they are looking for.
Other folks have reported that the AppStore app has prompted them to download a retailer's app when in the vicinity of the retail store, but this has yet to be substantiated. See here: Can I get my iOS app to appear on the lower left corner of the lock screen?
There is no publicly announced way to register a beacon with the AppStore to trigger this behavior, although it is possible it is part of some private deal or trial effort between Apple and third party retailers.
If anybody else sees this behavior, please report the name of the retailer and the location so others can try to reproduce.
This is all available from Apple. You can read more in this document.
Essentially, you create a UUID that you embed into all the iBeacons that you want to use with your app. Then your app has this UUID too so it knows when iBeacons are around that you are interested in.
Top of page 3 in the linked document.
