I think the thing I dislike about Duolingo is it sort of catches the casual person into a trap by misleading them into thinking that by using this app they'll learn another language. It's not that it's a bad app, it's just that that's not going to happen. There's no one resource that will get you to even an intermediate level in a language. And the State Department's FSI estimates are unfortunately pretty accurate fo…
Same problem as dating apps: if you could actually learn a language with Duolingo, then you would stop using Duolingo. No good for business.
The hard part is how to trick people into believing that it works or even "it's better than nothing". Hence gamification.