Евгений

$(document).ready(function() {
  var scrollTop,
    flipptext = true;
  $(window).scroll(function() {
    scrollTop = $(this).scrollTop();
    if (scrollTop > 100 && flipptext == true) {
      flipptext = false;
      $(".intro").flipping_text({
        tickerTime: 50,
        tickerCount: 5,
        customRandomChar: "!@#$%^&*"
      });
    }
  });
});

<a href="" data-link="block1">1</a>
<a href="" data-link="block2">2</a>
<a href="" data-link="block3">3</a>

<div id="block1" class="block">Открыт блок 1</div>
<div id="block2" class="block">Открыт блок 2</div>
<div id="block3" class="block">Открыт блок 2</div>

$(document).ready(function () {
        $('a').click(function () {
            var link = $(this).data('link');
            $('.block').hide();
            $('#'+ link).show();
            return false;
        });
    });

.box {
    background: blue;
    width: 50px;
    height: 50px;
    position: relative;
}

$('.responsive-menu-items > ul > li').each(function () {
        let el = $(this),
            link = $('> a', el),
            ul = $('> ul', el);
        if (ul.length && window.matchMedia("(max-width: 400px)").matches) {
            link.click(function () {
                ul.toggleClass('subcategories');
                return false;
            })
        }
    })