Web Fonts Social Icons WP
This plugin adds option to add Social Icons in post/page content and using widget. It adds new icon in TinyMCE toolbar in your content editor
Click the last blue star icon to open up a popup with shortcode generator.
Using it you can add this kind of icons
The pThe plugin is available to buy separately on CodeCanyon http://codecanyon.net/item/web-font-social-icons-widget-shortcode/5988988 but it's included in Holomatic theme