A simple Salesforce bot for Facebook Messenger.
See this blog post for details.
In Setup, enter Apps in the quick find box, and click the Apps link
In the Connected Apps section, click New, and define the Connected App as follows:
Make sure you are logged in to the Heroku Dashboard
Click the button below to deploy the Messenger bot on Heroku:
Fill in the config variables as described.
Follow these instructions to create a Facebook app. You'll have to create a Facebook page, a Facebook application, and configure Messenger for your application.
Visit the Facebook page you created in the previous step, and click the Message button. Type help in the chat bot. You can continue the conversation with the bot in the Messenger app on your phone or in the browser (http://messenger.com).