Not being able to see this sample project, it's hard to say for certain what it will take.
At bare minimum go into your project summary, and select "Universal" for the device support.
Above and beyond that, it just depends on what the app is and how it's structured. For NIBs, you will want a NIB for iPhone and one for iPad. I find it easy to abstract this away so that I can simplify my view loading:
MyController *myController = [[MyController alloc] initWithView:@"MyControllerView" bundle:nil];
Then in a category, I'd define initWithView similar to:
@implementation UIViewController (Universal)
-(id) initWithView:(NSString *)view bundle:(NSBundle *)nibBundle{
bool isIpad = UI_USER_INTERFACE_IDIOM() == UIUserInterfaceIdiomPad;
NSString *nibName = [NSString stringWithFormat:@"%@_%@", view, (isIpad ? @"iPad" : @"iPhone")];
return [self initWithNibName:nibName bundle:nibBundle];
}
@end
But, that's just one aspect of supporting both devices. In reality the subject is rather specific to the app you're working on. Things like OS support (e.g., am I only targeting iOS 6 or higher) play a factor in things.
