Apple picks its iPhone 'app of the year'

Duolingo, a free language-learning app for iOS and Android, might not be quite that popular, but it did catch the attention of Apple, which named it the top free iPhone app of 2013.

Released in late 2012, the app already has more than 10 million downloads and offers its language-learning services for six languages -- English, Spanish, German, French, Italian, and Portuguese. USA Today reports that Duolingo hopes to be able to offer more than 50 languages in the coming months. 

But what's most impressive is the business model the company uses to make money and keep the app free. Basically, the app's users do the work for the app, while learning, by translating web documents that companies pay Duolingo to translate. 

When it comes to the app itself, I haven't tried nearly as many apps as Apple, but I too found Duolingo to be a deceptively addicting and helpful tool. Every time I open it to refresh my Spanish, I find that I use the app much longer than I intend, no small feat for a medium where other apps and notifications are constantly vying for your attention. Sometimes, I'll even take some time to try out new languages. The feel of the app is like a quiz game with variety of ways to test your skills to keep things interesting -- it uses your microphone to test your speaking ability, for example -- but it does so without feeling oversimplified. Points and increased skill levels help push you to continue learning, even if you barely know what "hola" means. 

With the number of smartphone users skyrocketing around the world (and growth expected to continue), the way we communicate could be dramatically changing.