In Android you can use Fragments to develop only one app targeted to phones and tables, so you can have different UI. You can even use only Layouts and have some condition on the code to run tablet or phone logic.
I need to develop an app for iPhone and iPad and I wonder if there is something similar for implementing different UIs and slighty different behavior. In my case the iPhone app would use tabs at the bottom of the screen, but the iPad one should use the menu on the left side.