Freshdesk - Freshdesk is a cloud-based customer support software that lets you support customers through traditional channels like phone and email, social channels like Facebook and Twitter, and your own branded community
tawk.to - tawk.to is a free live chat app that lets you monitor and chat with visitors on your website or from a free customizable page
Heeduser - Heeduser is the customer engagement platform that helps companies build better relationships with their customers and prospects, through the better online customer community
Intercom - Intercom is a customer relationship management and messaging tool for web businesses. Build relationships with users to create loyal customers.
Userlike Live Chat - Userlike is free live chat software for website and mobile support.
Zendesk Chat - Zendesk Chat (formerly Zopim) is the fastest way to engage your customers with live chat software.