Amazon Lex - Harness the power behind Amazon Alexa for your own conversational apps.
Intercom - Intercom is a customer relationship management and messaging tool for web businesses. Build relationships with users to create loyal customers.
Zendesk - Zendesk is a beautiful, lightweight help-desk solution.
Faqbot - Build your chatbot for FAQ, sales and lead generation automation.
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
Dialogflow - Conversational UX Platform. (ex API.ai)