Chatfuel - Chatfuel is the best bot platform for creating an AI chatbot on Facebook.
EssentialPIM - EssentialPIM is a free Personal Information Manager that keeps up with the times and lets you manage appointments, tasks, notes, contacts, password entries and email messages across multiple devices and cloud applications.
Landbot - An intuitive no-code conversational apps builder that combines the benefits of conversational interface with rich UI elements.
Todo.txt - Track your tasks and projects in a plain text file, todo.txt. A todo.
ChatBot - Easy to use chatbot platform for business
Task Coach - Task Coach is a simple open source todo manager to keep track of personal tasks and todo lists.