JSFiddle - React, Tailwind, and code Playground

HTML

<img class="call-to-action" src="http://www.iconarchive.com/download/i83646/pelfusion/long-shadow-media/Mobile-Phone.ico" alt="phone">

CSS

.call-to-action{
  width:75px;
  position:fixed;
  right:10px;
  bottom:10px;
  animation: pulse_animation 1s linear infinite;
}
@keyframes pulse_animation {
    0% {
        transform: scale(1);
    }
    30% {
        transform: scale(1);
    }
    40% {
        transform: scale(1.08);
    }
    50% {
        transform: scale(1);
    }
    60% {
        transform: scale(1);
    }
    70% {
        transform: scale(1.05);
    }
    80% {
        transform: scale(1);
    }
    100% {
        transform: scale(1);
    }
}