The previous technique shows how you can modify the Targeted Device Family setting to create a single application that runs on both the iPhone and the iPad, called a Universal application. The challenge is adapting the UI of the application for each platform — you have to programmatically detect the type of device the application is running on and then modify the layout of the UI dynamically.
Apple recommends that you create a Universal application, one that targets both the iPhone and the iPad, with separate XIB files representing the UI for each platform. The following Try It Out demonstrates how you can create a Universal application.
TRY IT OUT: Creating a Universal Application