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
Issuetrak - Issue tracking software for help desk and customer service
LiveChat - LiveChat - premium live chat software. Approach customers directly on the website, make connections and drive more sales using LiveChat.
Deskun - Deskun is a Help Desk system inside Gmail. It enables you to support customers directly from your mailbox, manage projects, and use free features for Gmail.
Crisp Chat - Multi-channel customer support software
Kapdesk - Kapdesk offers support teams with a helpdesk software to streamline support tasks.