This is actually an app that I heard about from Twit's All About Android show last week. Although it is a fairly new app, and was just updated over the weekend. It also has between 100,000 and 500,000 downloads already. With Duolingo you can learn all kinds of new languages easily, free and fun. Duolingo touts that there are no ads or in-app purchases. Making this app completely free. You can get a college-quality education from this app, at least according to the developers.
Duolingo is also fairly fun to use. You'll lose hearts for answering incorrectly, advance by completing bite-sized lessons, and track your progress with shiny achievements. Duolingo is constantly improving. The developers bust out the lab coats regularly and measure how well you learn on Duolingo. Making your learning experience better over time.
Some of the languages that Duolingo can teach you is Spanish, French, German, Portuguese, Italian, and English. The app is sitting at version 1.0.4 at the time of writing this, and it weighs in at about 5.9MB so it's not an entirely large app. But definitely something worth your time. If you've been looking to learn a new language, this is probably the best way to do it.
Duolingo, as we've said already, is free and available in the Play Store now.