Zendesk - Zendesk is a beautiful, lightweight help-desk solution.
UserVoice - UserVoice integrates easy-to-use feedback, helpdesk, and knowledge base management tools in one platform that empowers users to speak and companies to understand.
WATI - No-code chatbot builder for WhatsApp Business
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
SleekFlow.io - Sell, convert & support better on chat
Front - multi-channel inbox service for collaborative teams