How does the Navita TEM app get call log information?

Question

How does Navita https://itunes.apple.com/us/app/navita-t.e.m.-personal/id590228620?mt=8 manage to display a call log?

If I swipe the app out of the task manager then it

Answer 1

Here is what I've found from Navita TEM disassembly and it's resources.

Application uses two background modes - location and audio. You can see it in the Info.plist file. When you enable phone calls logging application will also enable "alerts" and "Real-time" switches. When "alerts" enabled application infinitely loops in background "bg-sound.mp3" file which has no sound, it's just silence. Because of that it doesn't use hacks like this one How to get a call event using CTCallCenter:setCallEventHandler: that occurred while the app was suspended? . It's similar trick to location used in order to keep the app running in background and receive phone call events. Somehow this was not rejected from the AppStore.