The HelloContacts app is complete for now. The next few chapters will focus on improving it with a new layout, a detail page, and a couple more changes. You've covered a lot of ground on the way towards iOS mastery. You've used Auto Layout, the Contacts framework, you learned about delegation, custom table view cells, and you've implemented several delegate methods to implement several features on your table view.
If you want to learn more about UITableView, I don't blame you! The table view is a very powerful and versatile component in the iOS developer's tool belt. Make sure to explore Apple's documentation because there is a lot more to learn and study. One of the most important patterns you learned about is delegation. You'll find implementations of the delegate pattern throughout this book and UIKit. Next up? Converting the UITableView to its even more powerful and interesting sibling, UICollectionView.