It's possible to write a simple app with a handful of pages. Ionic provides a lot of out-of-the-box components that allow simple plug-n-play operations. When the app grows, managing different views and their custom data at a specific time or triggered event could be very complex. Ionic 2 comes with some changes in handling state and navigation. In Ionic 1, you could use UI-Router for advanced routing management mechanism. In Ionic 2, NavController will enable the push/pop implementation of the navigation.

Since Ionic 2 introduces many new components, you have to understand how these components impact your app state hierarchy and when each state is triggered.