The author, Brent Schooley, built a meme generator using Twilio MMS, Imgflip, and Sinatra. The app matches incoming text messages against a list of supported meme formats and creates a corresponding meme image using the Imgflip API. If the message doesn't match a format, it returns a prompt to send "list" for a list of valid memes. When a matching meme is found, it sends an MMS with the generated image back to the user's phone. The app can be deployed on Heroku and users can test it by sending a valid meme sentence or using pre-configured Twilio numbers in the US or Canada. The author plans to add more features to the app, including support for custom memes and sharing them with friends.