This article demonstrates how to build an ASP.NET Core web application that uses Twilio Programmable SMS and the Twitter API to receive notifications when someone mentions you on Twitter. The application allows users to retweet these mentions with a quick text response, without having to install an app on their phone or open their phone's browser. The project requires setting up a Twitter developer account, creating a Twilio phone number, building an ASP.NET Core web application, and deploying it to Azure. The application uses the Tweetinvi library to interact with the Twitter API and the Twilio.AspNet.Core library to handle SMS messages. Once deployed, the application can be tested by sending mentions on Twitter, which will trigger text message notifications that can be responded to with a quick "Yes" to retweet the mention.