Twentyei is a Facebook Messenger chatbot by Sanil Chawla that adds some useful and fun enhancements to Messenger group chats.
The current version is 2.0.0 a1. Differences include a migration to ES6, moving to facebook-chat-api instead of my hacked-together custom solution, a more elegant codebase, and more.
More complete documentation and a changelog will be published soon, which will cover available functionality and instructions to run your own Twentyei.