Simplify, simplify, simplify.
Many times your enterprise in-house apps will be derived from an existing desktop application environment, or based on line of business systems that your users depend on. Its easy to fall into the trap of attempting to bring every feature and function from the desktop app down to the mobile device. This approach will usually not deliver the type of experience users expect nor need given the mobile context. Remember that users have different needs for how they might approach or accomplish certain tasks on a mobile device, and certain tasks might not be practical for a mobile device at all. Small, bite sized tasks are better suited to mobile development, which is why its important to continually filter your features through your application definition statement as you look to refine your app.
iPhone and iPad users are accustomed to the appearance and behavior of the built-in apps that ship with each device. You donʼt want to mimic every detail of the built-in apps, but itʼs helpful to understand the design patterns they follow, and consider how to apply that structure to your own apps in a simple, functional, and easy to use design. Investigate these apps for common controls, touch events (such as pinch and zoom), and animations, and start to think about how you might apply those concepts to your own app in a consistent way.
Read the Case Studies: Transitioning to iOS