I've been browsing the app store and found 2 examples of commercially-successful apps that boast being able to run accelerometer-based algorithm with the phone locked (power button pressed). These apps are "Sleep Cycle Alarm" and "Smart Alarm Clock"
I see quite a lot of Q and A from 2010, 2011 which say that it is impossible to continue using accelerometer when the user locks the device. Yet I see that at least two apps have this feature available. This is why I'm asking - is there some new API or workaround that exists as of October 2012 that allows app developers to run accelerometer with the phone power button pushed (phone locked/asleep)? Or is it a secret API that is only available to top-selling apps?
Thank you for your input! I know there are dozens of questions like that, but I'm looking for the most recent information from 2012.