If you're looking for helping studying a foreign language, the Polyglot app for Android was designed with you in mind. All language materials are divided into topics, and each topic contains a list of words to learn: from English to Spanish.

The app can also download each language lesson to your Android's SD-card, which allows you to listen and study the lessons without Internet access. Additionally, all lessons listened to using the Internet are automatically saved on your Android's memory card.