Triggers a CSS animation from JS without class manipulation. Wrapped in a promise that resolves when animation is completed. Easily chainable. >IE10 when transpiled. Demo: http://jsbin.com/qibilaxehi

animate.js

function animate (el, animationName, durationMs) {
  return new Promise(res => {
    
    const fn = e => {
      if (!e.target.isEqualNode(el)) return false
      el.removeEventListener('animationend', fn)
      el.removeEventListener('webkitAnimationEnd', fn)
      el.style.animationDuration = ''
      el.style.webkitAnimationDuration = ''
      el.style.animationName = ''
      el.style.webkitAnimationName = ''
      res(el)
    }
    
    el.addEventListener('animationend', fn)
    el.addEventListener('webkitAnimationEnd', fn)
    el.style.animationDuration = durationMs + 'ms'
    el.style.webkitAnimationDuration = durationMs + 'ms'
    el.style.animationName = animationName
    el.style.webkitAnimationName = animationName
    
  })
}

document.querySelector('a').addEventListener('click', e => {
  
  let queue = Promise.resolve()
  for (let h3 of document.querySelectorAll('h3')) {
    queue = queue.then(() => animate(h3, 'pulse', 1000))
  }
  queue = queue.then(() => alert('done'))
  
})

native-animations.html

<a href="#">click me</a>

<h3>We are gonna be animated one after the other</h3>
<h3>We are gonna be animated one after the other</h3>
<h3>We are gonna be animated one after the other</h3>
<h3>We are gonna be animated one after the other</h3>
<h3>We are gonna be animated one after the other</h3>
<h3>We are gonna be animated one after the other</h3>

style.css

@keyframes pulse {
  from {
    transform: scale(1);
    transform-origin: center center;
    animation-timing-function: ease-out;
  }
  25% {
    transform: scale(1.1);
    animation-timing-function: ease-in;
  }
  50% {
    transform: scale(1);
    animation-timing-function: ease-out;
  }
  74% {
    transform: scale(1.05);
    animation-timing-function: ease-in;
  }
  to {
    transform: scale(1);
    animation-timing-function: ease-out;
  }
}