The author of this article, Phil Nash, created a fully functional web application using Twilio to send and receive SMS messages. The app uses the Service Worker API to push notifications to users when new messages are received. To achieve this, the developer installed the Service Worker from the front end of their application, got user permission to send push notifications, wrote the Service Worker code to handle incoming push notifications, and updated the back-end to receive webhooks from Twilio when it receives an SMS for its number. The article covers the process in detail, including setting up a Twilio account, cloning the base application, installing dependencies, creating a Service Worker, storing the endpoint on the server-side, triggering push notifications, and adding support for Chrome using the Google Cloud Messaging service. The author also discusses how to use the web-push module to send push notifications across different browsers.