In this chapter, we studied application lifecycles and states for both iOS and Android platforms. For iOS platforms, we examined how the AppDelegate class can be used to respond to changes in the application state. Also, we looked at the methods associated with state changes in the UIViewController class. For Android platforms, we examined how an application's lifecycle is linked to that of its Activities. We looked at the methods that can be used to respond to changes in an Activity's state, and how to respond to a rapid configuration change event. Finally, we examined backgrounding from a generic point of view including the most important concerns that must be addressed for an app that is transitioning into a background state.

In Chapter 7, Testing and Debugging, we're going to discuss the tools available to test your applications including unit test projects, debugging tools, simulators and emulators, crash logs, TestFlight, and platform-specific suites of tools.