jomol

Simple Font Awesome Icon plugin will give you the Font Awesome Icon option in your post and page. From there you can choose the required icon and hit save. Then use the get_post_meta(‘post ID’, ‘font-awesome-icon’, true); function in the template file and you will get the class name which can be used with i tag.
Please take a look the plugin page for more details: [https://codingdom.wordpress.com/simple-font-awesome-icon/)

Simple Font Awesome Icon

Simple Font Awesome plugin will give you the option for adding Font Awesome icons for your post and pages in the form of a meta box.

strx

Beautiful CSS3 buttons support, created by the ZURB team
<a href="http://www.zurb.com/blog_uploads/0000/0617/buttons-03.html" rel="nofollow ugc">Buttons demo</a>
<a href="http://www.zurb.com/article/266/super-awesome-buttons-with-css3-and-rgba" rel="nofollow ugc">Zurb Blog</a>
See also: <a href="http://www.strx.it/2010/11/wordpress-css3-buttons/" rel="nofollow ugc">Official Blog Post</a>

Simple Font Awesome Icon vs Strx Zurb CSS3 Awesome Buttons