This article describes how to use C#, Azure Functions, and Twilio to send daily SMS reminders. The service uses an Azure Table to store phone numbers that have subscribed to receive updates. When a new message is received from Twilio, the function checks if the text contains "subscribe" and adds or updates the phone number in the table accordingly. A second Azure Function runs daily at a specified time using a timer trigger to send SMS reminders to all users who have subscribed. The service uses Twilio's REST client to interact with the Twilio API and send messages.