Duolingo for Android is a free trending language learning app with which you can easily learn a second or third language. The method of learning is immersive, allowing you to pick up new vocabulary and new expressions with ease. The app tests your memory through a variety of tasks, such as matching definitions, fill-in-the-blank sentences, and conjugations. After each task, you can see your score and, if you succeed, move on to the next step.

Key Features

More than 35 languages, including Spanish, German, Chinese, Hebrew, Turkish, Arabic and more.
The courses can be taken online from the website or from your mobile application.
Your progress will be tracked so that you can pick up each day from where you left off.
Fun game-like lessons.
Learning through all 4 types of language proficiency skills: speaking, reading, listening, and writing.
Free.