Animate.cssとwow.js

<!-- animate.css -->
<link
  rel="stylesheet"
  href="https://cdnjs.cloudflare.com/ajax/libs/animate.css/3.6.2/animate.min.css"
/>
<!-- wow.js -->
<script src="https://cdnjs.cloudflare.com/ajax/libs/wow/1.1.2/wow.min.js"></script>

<script>
new WOW().init();
</script>

<div class="box wow animated fadeInUp">fadeInUp</div>
<div class="box wow animated fadeInDown">fadeInDown</div>
<div class="box wow animated fadeInLeft">fadeInLeft</div>