Smallchat Beta - Slack integration for chatting with visitors to your website
Talkus - Chat with your website users from Slack
Intercom - Intercom is a customer relationship management and messaging tool for web businesses. Build relationships with users to create loyal customers.
Slacking Pigeons - Chat in real time with your users directly from Slack
Avochato - Text messaging for your business.
Zopim - Live chat is a faster and more personal way for you to engage your customers. Free for 14 days. No credit card required.