Do you remember the last time you were in a situation where everyone around you spoke a language you couldn’t understand, and all of a sudden, you felt like a foreigner (even sometimes in your own country)? How vulnerable did it feel not to understand a word being said? For this reason, and many others, Duolingo was created — an app that teaches you a new language in a fun and playful way. The experience of the app is one of the most positive for a number of reasons:

• I feel like I’m getting more than I came for.
• The creators designers of the app thought about and considered many ways to engage a user.
• I always know what I’m expected to click in order to move forward.
• No one’s selling me anything.
• It’s gamified to the right extent (playful without being too childish).
• It make’s me feel good.
• Memorable.

When people use the word “clean” to describe an app that they like, I’m a bit resentful, because there are more than enough apps out there that may look “clean” but have terrible usability attributes. Also, “clean” isn’t a bonus-feature of UI, it’s a benchmark for how apps should be designed. When you throw a user to an experience that’s too busy or give them too many choices, they’re likely to just leave the app altogether. Duolingo does a great job of keeping things simple, focused, interesting and surprising all along the way, which may be the reason this app has been on my phone for over three years.