Challenges in developing an application for iPhone and Android using Titanium

Can 开发者_StackOverflow中文版someone who have developed apps for iPhone and Android, tell the challenges that we would be facing when developing using Titanium?

UPDATE:

My question is based on the following perspective: UI Design, layout differences in iPhone and Android, supporting multiiple devices in Android.

First difference I have found so far is in the implementation of the NavigationBar and NavigationController.

The way you implement it for the iphone is different from the way you would implement it for the Android device. I would also add that the way you implement the UI for the iPad is also different.

I have had to refactor my code to seperate the UI implementation from the other services so I can try to not have too much duplicated code. I will use this approach when I port the solution to the Android Platform