Integration steps:
  1. Visit the site: https://engage.social/
  2. You should create an account and follow the instructions to create your campaign.
  3. When you’re finished you will be redirected to http://go.engage.social/user/widget, where all the necessary snippets will be listed.

Social sharing button for default campaign has next code snippet:

  <script src="//widget.engage.social/js/enshare.js"></script>

  <a id="engage-social" href="javascript:void(0);" onclick="ENGSL.loadShare('d385chnjsx8zyuwtw43i');return false;">
    <img src="https://engage.social/images/engage.social_152px.png" title="FABL Visitor Share" alt="Social Share Icon">
  </a>
  
  <style>
    #engage-social img:first-of-type {
      width: 8%;
    }
  </style>

Take a look on this button!

Social Share Icon