UIAlertView (basic)

gistfile1.m

    UIAlertView *alert = [[[UIAlertView alloc] initWithTitle:@"Opened from URL" 
                                                     message:@"App opened trough URL" 
                                                    delegate:self 
                                           cancelButtonTitle:@"Ok" 
                                           otherButtonTitles:nil] autorelease];
    // optional - add more buttons:
    [alert addButtonWithTitle:@"Yes"];
    [alert show];

//
// Protocol method of <UIAlertViewDelegate>
//
- (void)alertView:(UIAlertView *)alertView didDismissWithButtonIndex:(NSInteger)buttonIndex {
    if (buttonIndex == 1) {
        // do stuff
    }
}