If that is possible then please suggest me a good online live chat solution which is easily integrated in any third party application such as WordPress, Joomla, Drupal, Sales-force, Shopify etc.
I use zopim, it is free for 1 user
Yes ! it's possible, for this purpose you may try eAssistance Pro live chat plugin
I also use Zopim, highly recommended, and very easy to install and manage.