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

Freshdesk - Freshdesk is a cloud-based customer support software that lets you support customers through traditional channels like phone and email, social channels like Facebook and Twitter, and your own branded community

JivoChat - JivoChat is a live chat that enables you to talk to visitors on your website

LiveAgent - LiveAgent is a fully-featured web-based live chat and help desk software. It harnesses the power of a universal inbox, real-time live chat, built-in call center, and a robust customer service portal. Start your free 1 month trial today!

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

Zendesk - Zendesk is a beautiful, lightweight help-desk solution.