When BotEngine was released, I was an instant customer. I built and deployed bots on at least four other platforms while waiting for BotEngine and every one of those platforms was problematic. Either they weren't reliable and would malfunction without warning, or they were free and then not free and then kind of free and then not, etc, so i would gladly recommend.
ChattyPeople helps you build custom chatbots for Facebook and Slackbot. The platform can teach you the skills you need to make chatbots. It makes custom chatbots for small businesses, e-commerce, and enterprises. ChattyPeople thus creates, tests , deploys, and manages the bots within the chosen messaging app. It also provides you bot analytics to optimize the customer experience.