Just a small note, If you switch the Facebook API Key and Secret from Wordbook's to your own personal applications'. You can select what icon the post will show. You also need to update the template_id. Here is how I did it:
Primary One Line Template
{*actor*} updated <a href="http://Feli.pe">Feli.pe</a>
Primary Short Story Template Title
<a href="http://feli.pe">Feli.pe</a> : <a href="{*post_link*}">{*post_title*}</a>
Primary Short Story Template Body
{*post_excerpt*}
Action Links
read more - {*post_link*}
Drawback from this for the Wordbook guys is that they loose control of their app analytics and they cant track how many users are using it so make sure you make a donation to the guys for their efforts. Just a FYI though. It's what I did :)