With that, our application is complete. It's not a perfect application, but it is a complete Android application, which demonstrates a number of features you might need in your own app including Activities, services, database creation, content providers, messaging, and asynchronous processing. Clearly, there are parts of the application where the error handling could be more robust, or the design generalized a bit more to be more readily reusable. Doing so in this context, however, would obscure the basics of the application too much. Making these changes, then, will make a great exercise for the reader.
In the next chapter, we'll take a look at a completely different type of application. We'll build a small utility to handle what can be a serious problem--too much email. This application will allow us to describe a set of rules that will delete or move emails. It's a simple concept, but it will allow us to work with JSON APIs and the JavaMail package. You'll learn a bit and end up...