Adding a button for live chat on my website

Hi
I am trying to add a button that will be linked to live chat page for my website, but i want the button to be in the style of the social share buttons, please refer to http://www.addthis.com/ page for the type of styling used for the social share button. Can anyone please suggest me if there is any plugin / codes that can make these type of buttons wherein a url can be added to the button manually.
Really appreciate the help.

Thanks in advance