Duolingo
“Duolingo built the most addictive habit loop in education — 500 million users who genuinely panic when they miss their streak, gamification so effective it made learning Spanish feel like Candy Crush, and a green owl that haunts your notifications with the persistence of an ex. The exquisite irony is that they perfected the art of making language learning compulsive just as ChatGPT made fluency optional for most of what people thought they needed Spanish for.”