Rovie is an underwater robotic friend of Twilio's, created by Ricky Robinett and fellow Developer Evangelist Brent Schooley. They built Rovie using an OpenROV, a low-cost underwater robot for exploration and education, with the cockpit software being a Node.js application. The team modified the application to receive text messages from Twilio, allowing Rovie to send pictures back to whoever sent the message. To make this work, they used ngrok to open up their localhost to the outside world, enabling them to share Rovie's underwater adventures on social media platforms like Twitter and Facebook.