Duolingo is a mobile app designed to help people learn and practice a new language. Users can select any one of 36 languages and practice reading, listening, and speaking this language. The app works by introducing users to new vocabulary and grammar rules through a series of short levels. The goal? Users will learn by seeing words and grammar modeled. Next, users can try their hand at interpreting written and spoken sentences and then speaking them out loud, allowing for pronunciation practice. When users are able to successfully complete these tasks they move onto higher levels with new vocabulary. Duolingo is designed to be of use to individuals brand new to a language as well those looking to brush up an already familiar one, as users can chose to test out of levels. Best of all, Duolingo is free. Users can also "compete" against friends using the app if they wish, providing additional motivation and accountability.