Intercom - Intercom is a customer relationship management and messaging tool for web businesses. Build relationships with users to create loyal customers.

Talkus - Chat with your website users from Slack

Live Chat by Sumo.com - Instantly communicate with customers, prospects & visitors

Drift - A messaging app that helps you grow your business.

Keeping - Turn Gmail into a Fully Functional Helpdesk

Crisp Livechat - The most modern experience to talk to website visitors