Elsa Prieto, 27, France

Elsa Prieto is the technical director and co-founder of Pili Pop, a language learning app for children.

Pili Pop English has been downloaded more than 500,000 times, and the company has just released Pili Pop Espanol for learning Spanish.

Her advice for future entrepreneurs: "Don't be afraid to fail, a person who never made a mistake never tried anything new."

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