So this was pretty fun. I was shown this watch-me-build-this effect Codepen @ http://codepen.io/jakealbaugh/full/PwLXXP/ and I was blown away. I thought it was really cool, so I decided to dissect the code and recreate it myself.
It turns out the idea is not complicated at all. Basically you have a string that is the final output of the CSS, and then you slowly add the CSS string into a style element. Add a little interval to keep adding to the string and inject into the style element and you can simulate typing (there's no backspaces, so it's the most realistic simulator lol).
Love to experiment new things that I find interesting. Thanks Kris Giamello for showing me this!
Here's the link if you are on mobile: http://codepen.io/mikemunsie/pen/mygGQZ/