Dialogflow - Conversational UX Platform. (ex API.ai)
BotList - An app store for bots
Telegram - Telegram is a messaging app with a focus on speed and security. It’s superfast, simple and free.
ManyChat - ManyChat lets you create a Facebook Messenger bot for marketing, sales and support.
Botpress - Open-source platform for developers to build high-quality digital assistants
Chatbot Templates - 50+ bot templates you can use in one click