In 2018, language learning app Drops was named Google's "best app of 2018," surpassed 10 million downloads, and saw revenue increase fivefold.

The app claims users can learn a new language — it currently offers more than 30 — with minimal time and commitment.

But according to co-founder and CEO Daniel Farkas, it took a huge failure to put him on the right track to building a successful platform.

"Being European I realized quickly that speaking more than one language was the key to the global marketplace," the Hungarian entrepreneur said.

Farkas' idea for an app stemmed from his own experience of trying to learn a language as quickly as possible, when he noticed a gap in the market for a quick-fix solution. Eventually, he and co-founder Mark Szulyovszky developed LearnInvisible — but although the app had all the tools required to learn a new language, users were bored and didn't commit for long enough to learn anything.

"We had to learn the hard way that our first baby was a bit ugly. It was really hard," Farkas told CNBC. "But we're really conscious of our mistakes and have spent a lot of time analyzing what went wrong — we realized that effectiveness alone is not enough. With LearnInvisible, people just didn't come back after trying it. So we decided to start from scratch."

The co-founders decided to incorporate all of the educational effectiveness of Learn Invisible with a more engaging concept, and launched Drops in 2015.

"We basically decided to build a game, but this is a game with a more noble purpose," Farkas said. "Boredom is the learner's enemy, so we have a lot of focus on visuals — we are obsessed with design and wanted to build a beautiful design."

They were also mindful of knowing an app's limitations. Users of Drops learn by associating images with words in a gaming format, but the platform doesn't delve into the complicated depths of individual languages.

"Drops focuses on vocabulary because we want to do one thing really well — we don't offer a whole menu of language knowledge, such as grammar," Farkas explained. "We do not believe an app is able to get you to fluency — acquiring all of that knowledge best done by practicing with a teacher. And we are not filling the teacher's role."