Tab Bar covers TableView cells in iOS7

Try this for your CustomViewController:

- (void)viewDidLoad
{
    [super viewDidLoad];

    UIEdgeInsets adjustForTabbarInsets = UIEdgeInsetsMake(0, 0, CGRectGetHeight(self.tabBarController.tabBar.frame), 0);
    self.scrollView.contentInset = adjustForTabbarInsets;
    self.scrollView.scrollIndicatorInsets = adjustForTabbarInsets;
}