Passing Data from App delegate to View Controller

Interface:

@interface MyAppDelegate : NSObject  {
  NSString *myString;
}
@property (nonatomic, retain) NSString *myString;
...
@end

and in the .m file for the App Delegate you would write:

@implementation MyAppDelegate
@synthesize myString;
    myString = some string;
@end

Then, in viewcontroller.m file you can fetch:

MyAppDelegate *appDelegate = (MyAppDelegate*)[[UIApplication sharedApplication] delegate];
someString = appDelegate.myString;  //..to read
appDelegate.myString = some NSString;     //..to write