Design Critique: Duolingo (Web APP)

Duolingo

Duolingo is an app that assists people to learn different languages in an interesting way. First, it makes users gain achievements, in a game way, when learning. Second, it is free for users to learn languages without a financial burden. Now, being a user since 2017, I am going to apply the concept of Don Norman’s “The Design of Everyday Things” to critique this app (Web version).