Avochato - Text messaging for your business.
Smallchat Beta - Slack integration for chatting with visitors to your website
Message Me - Website to create your contact business card
Intercom - Intercom is a customer relationship management and messaging tool for web businesses. Build relationships with users to create loyal customers.
StackWhats - Add the WhatsApp Live Chat to your website
Talkus - Chat with your website users from Slack