View source for iOS Foreground and Background

== Handling Foreground and Background states ==
For iOS, background/foreground detection is handled by the app lifecylce APIs which are provided by [https://developer.apple.com/library/content/documentation/iPhone/Conceptual/iPhoneOSProgrammingGuide/TheAppLifeCycle/TheAppLifeCycle.html Apple:]

Foreground/Background state measurement is a requirement of Nielsen AppSDK implementation which is especially crucial for static measurement.