Duolingo, Inc. (DUOL) is an education-technology company developing mobile learning products led by the Duolingo language-learning application. Its artificial-intelligence, data-analytics and gamified products include Super Duolingo, the Duolingo English Test, Duolingo for Schools, Duolingo ABC and Duolingo Math. Revenue comes primarily from subscriptions, third-party in-app advertising, the Duolingo English Test and in-app purchases, with customers in the United States and other markets.