Layar staff has not been able to reproduce this at the moment and has checked the code and every single view controller in our app that uses the location services shuts them down as it should when the app goes in the background. 

Currently it looks more likely to be an iOS glitch: If you dismiss the app from the springboard, then completely restart the phone, the location arrow still appears next to the app, where in fact it's impossible that the app is using the services as it hasn't even been started since the restart of the device.

Note that Layar isn't requesting location push notifications by the system when it's not running (something apps can do nowadays but need to register specifically for).

In the meantime, we will continue to look into this issue.