MessageBird Chat API - Connect with your customers through different messaging apps
Aivo - Skyrocket your Customer Service and Sales KPIs with a Chatbot powered by Artificial Intelligence. Give time back to people.
Wavecell - Wavecell simplifies real-time cloud communications using SMS, Chat Apps, Video Interaction and Voice solutions.
Zendesk Answer Bot - Chatbots
Twilio - Brings voice and messaging to your web and mobile applications.
Tars - TARS enables users to create chatbots that replaces regular old webforms.