Intercom - Intercom is a customer relationship management and messaging tool for web businesses. Build relationships with users to create loyal customers.
WhatsHelp - Communicate personally with your customers via Messenger
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
Chatra - Live chat software that helps to increase revenue and collect feedback providing an easy way for website owners to talk to visitors in real time.
JivoChat - JivoChat is a live chat that enables you to talk to visitors on your website
HeyHi.sg - Video call with interactive whiteboard