Structure Your App
To implement your software, you will make design decisions based on how you’d like to structure your app in terms of organizing your code into classes. To decide your iOS app structure up front, the top-down approach and model-view-controller (MVC) design pattern are recommended and actually embedded in the iOS SDK and tools. MVC is also implicitly embedded in Android SDK (with different vocabularies), and if you are used to the top-down approach for creating your Android apps, where you design the application workflow prior to detailing each individual screen, it is even easier for you to switch your programming thinking process between iOS and Android.
In this first step, you are aiming at class-level mapping ...