Responsive Live Chat Plugin for Responsive Themes, Any recommendation?

@Richard, how do you use Zopim chat so that each listing owner has their own chat window? As far as I know Zopim chat is only used between the site owner and visitors (I use Zopim on few of my sites).

@Sukanta – It does not look that it would be possible to use for chatting between ‘buyers’ and ‘sellers’, only between the site owner and visitors. Can you please confirm whether it is possible?