Gina Gotthilf, vice president of growth, at Duolingo joined Cheddar to discuss the launch of its Chinese course, the most asked of course since Duolingo's launch in 2011.

She said it's taken the company so long to launch the course because the app wasn't designed to teach characters and "tones", which are the fundamentals of the Chinese language.

The lessons are based on themes like greetings, food, travel, sports, business/finance, culture and even Chinese internet slang.

Gotthilf says one of the reasons Duolingo has taken off is because of the "gamifying" aspect of learning. It aims to make using the app in line for coffee, on the train to work, or waiting for a flight is fun and quick. People can learn at their own pace while being entertained in the process, she said.

The company has raised total of $108.3 million in funding and is currently valued at $700 million. The future plans aren't to keep adding new languages, but to increase the efficiency of the courses already launched. So far, 200 million subscribers have started learning a new language.