http://blog.rainy.im is using ghost, {{ghost_foot}} injection was used to append donate button to every article.

ghost_foot.html

<script type='tmpl' class='donation'>
<pre>
<code class="language-javascript">
if(post.content.isHelpful){
  $("button#donate").click();
};
</code>
</pre>
<button
  type="button"
  height=20
  class="am-btn am-btn-secondary am-btn-block am-radius am-btn-xs"
  data-am-modal="{target: '#donate-modal', closeViaDimmer: 1, width: 450}">
  <i class='am-icon-btc'/>
  BUY ME A CUP OF COFFEE
 </button>
</script>
<div class="am-modal am-modal-alert" tabindex="-1" id="donate-modal">
  <div class="am-modal-dialog" >
    <div class="am-modal-hd">
    </div>
    <div class="am-modal-bd">
        <div>
        	<img src='http://7xiijd.com1.z0.glb.clouddn.com/tenpay.png'
                 style="float:left" width=200 />
            <img src='http://7xiijd.com1.z0.glb.clouddn.com/alipay.png' 
                 style="float:right" width=200/>
		    <div class="clear" style="clear:both"></div>
        </div>
    </div>
    <div class="am-modal-footer">
    	<span class="am-modal-btn">NO, THANKS!</span>
    </div>
  </div>
</div>

<script>
    (function(){
        $(".am-article > .entry-content").append($('.donation').html());
        $("p").has("img").css("text-align", "center");
    })();
</script>