ScrollReveal.js - Awesome OnScroll Animations

ScrollReveal.js is a library to "easily reveal elements as they enter the viewport." It’s very small in size, as its weight is roughly 9Kb. It has no dependencies, so you don’t need to add other libraries to use it. In addition to the nice effects it supports, what you will really love about this library is that you can use natural language to define the animation you want to run:

<p data-sr="enter left and move 100px over 0.5s wait 0.1s"></p>

ScrollReveal