A Twilio Functions application was built to monitor cryptocurrency prices using CoinMarketCap's API and send SMS updates about price changes. The application uses Twilio's serverless environment, JavaScript, and the got module to make HTTP requests to CoinMarketCap's API. The application sends an SMS message with the current price of a specified cryptocurrency, including its symbol, price in USD, and percent change in 24 hours. The application also handles errors by catching any exceptions that occur during the HTTP request or when parsing the response from CoinMarketCap's API.