Bootstrap Magic - Create your Bootstrap 4.0 themes easily with magic
Dialogflow - Conversational UX Platform. (ex API.ai)
HackerThemes - Bootstrap 4 themes and tools for web developers
Telegram - Telegram is a messaging app with a focus on speed and security. It’s superfast, simple and free.
Bootstrap 4 Cheat Sheet - An interactive Bootstrap 4 cheat sheet
Botkit - Botkit is an open source developer tool for building chat bots, apps and custom integrations for major messaging platforms.