Intercom - Intercom is a customer relationship management and messaging tool for web businesses. Build relationships with users to create loyal customers.
GoSquared Live Chat - Beautiful, simple, and free live chat for your website
Talkus - Chat with your website users from Slack
Live Chat by Sumo.com - Instantly communicate with customers, prospects & visitors
Speaklyn - Website visitors chat with you on Facebook Messenger
Pepper - A friendly contact widget for your website