didSelectItemAtIndexPath of MainViewController.m from iPhone flat design UI http://www.appdesignvault.com/iphone-flat-ui-design-patterns/.

gistfile1.m

-(void)collectionView:(UICollectionView *)collectionView didSelectItemAtIndexPath:(NSIndexPath *)indexPath{

    StoryboardInfo* storyboardInfo = self.storyboards[indexPath.section];

    ControllerInfo* controllerInfo = storyboardInfo.controllers[indexPath.row];

    self.currentViewController = [self getControllerFromStoryboardInfo:storyboardInfo andControllerInfo:controllerInfo];

    UIViewController* controller = self.currentViewController;
    controller.view.frame = CGRectMake(0, 0, controller.view.frame.size.width, controller.view.frame.size.height);


    [controller.view addGestureRecognizer:self.swipeGesture];

    CGFloat yOffset = [controller isKindOfClass:[UINavigationController class]] ? -20 : 0;

    MBProgressHUD *hud = [MBProgressHUD showHUDAddedTo:controller.view animated:YES];

    hud.labelText = @"Swipe right to dismiss";

    controller.view.frame = CGRectMake(320, yOffset, controller.view.frame.size.width, controller.view.frame.size.height);
    [self.view addSubview:controller.view];

    [UIView animateWithDuration:1.0
                          delay:0.0
                        options: UIViewAnimationOptionCurveEaseInOut
                     animations:^{

                         controller.view.frame = CGRectMake(0, yOffset, controller.view.frame.size.width, controller.view.frame.size.height);

                     }
                     completion:^(BOOL finished){

                         [MBProgressHUD hideHUDForView:controller.view animated:YES];

                     }];
}