Isaiah Grey from Stamplay built a simple demo showing how to create an SMS weather alert service using Twilio and NodeJS. The service works by sending an SMS with a city name to a number provided by Twilio, which triggers a custom Code Block in Stamplay that fetches weather data for the city and assembles a response message. Another Stamplay Task then executes once the Code Block is complete, responding back to the initial SMS number with the weather data for that day. The service can be tested by sending a text to a Twilio number with a city name or "forecast" appended to it, and users should receive a response within several seconds.