The tutorial describes how to create a Slack app that sends SMS using Twilio and Laravel PHP. The process involves setting up a new Laravel project, creating a Slack app with slash commands, installing the necessary dependencies, and implementing the logic in the IncomingController class to send an SMS to a user tagged in the command. The tutorial also covers how to use the Slack API to fetch user details and Twilio SDK to send SMS. The final application is tested by sending a message from Slack, which triggers the Laravel application to send an SMS to the user's mobile number.