Just sharing with this with the community.
Recently I was looking for a live chat extension and I came across Chatbull on CodeCanyon. It's not a Magento extension but can be installed and used on Magento.
For $32 you get a full featured chat for your site plus they have an Android app (iOS coming soon), Windows and Mac desktop applications and browser based chat. It does have a few limitations - but you can submit a bug or feature request and they add it to future releases. Best part is no monthly fees, free upgrades, unlimited chat agents and departments.
Another option for you to refer : product questions extension You will certainly find it advanced and useful as great tool for communication between customer and seller. the price is far cheap about $ 39 with a decent set of features