Background applications on iOS devices are not the same as background applications on your Macintosh. There are a well-defined set of rules that iOS background-enabled applications you must follow to be considered "good citizens" of iOS 4.x. In this hour's lesson, you learned about the different types of backgrounding available in iOS and the methods available to support background tasks. Over the course of five tutorial applications, you put these techniques to the test, creating everything from notifications triggered when an application isn't running to a simple navigation app that provides background voice prompting.
You should now be well prepared to create your own background-aware apps and take full advantage of the latest and greatest feature of iOS 4.0.