This tutorial guides developers in creating a Flask application that sends SMS notifications whenever a product is sold on Gumroad using Twilio. To follow along, users need to have a free Twilio account, Python 3.6 or newer, Ngrok, a Gumroad account, and a Heroku account. The application uses environment variables from a `.env` file to store sensitive information such as the Twilio token and Gumroad API key. Once set up, the Flask application is deployed to Heroku and configured to send SMS notifications to a specified phone number whenever a sale occurs on Gumroad.