Question: I have a iPhone app and want to develop iPad app with the same name. I want to design different UI for ipad app including new features. So my question is, Will i have to make changes in iPhone app for iPad or need to create another new app for iPad ? Note: Name of both app will be same. Please explain how should i perform it.

Answer: 
What you describe is perfectly possible with [universal apps](http://developer.apple.com/library/ios/ipad/#documentation/iPhone/Conceptual/iPhoneOSProgrammingGuide/AdvancedAppTricks/AdvancedAppTricks.html). You will have to maintain to completely different hierachies of NIBs/Storyboards for your UI though. Controllers can be reused if you stick to the MVC pattern.
Here is a [tutorial](http://www.slideshare.net/cliffmcc/creating-a-universal-ios-application) for creating universal app(both for iPad and iPhone). Go through it