Rated 2 out of 5 stars
Not free. You have to buy it.
Rated 5 out of 5 stars
I used this extension for my shopping website, It allow me easily view my daily graph, online visitors and also chat with my visitors!
It is good if you have low visitors as it's price depend on that!
their support is fantastic, i received reply to my question in about less than 10 minutes.
It is very easy to integrate it on your site and get it's API code to use.