Duolingo offers courses on 42 languages, ranging from English, French, and Spanish to less commonly studied languages. Yet, Duolingo cannot correctly spell my geological engineer/exploration geologist daughter Évelyne's name, omitting accented character "É" in their e-mail message. Proper account creation process would have assigned "EvelyneSun".
Évelyne Sunatori -> velyneSuna
Potential Discovery or Invention
Although Duolingo specialises in languages, they make a fundamental error of "0 minutes" instead of grammatically-correct "0 minute".