I’ve watched my family grind on Duolingo for years with minimal retention. It’s a masterclass in engagement loops, but it feels increasingly unoptimized for actual fluency.

I’m a believer in the Pareto principle for language: mastering the 2,000 most frequent words gets you to ~80% comprehension faster than anything else. I spent other weekend 'vibe-coding' a simple app to test this approach for my Czech parents (learning English) and my Aussie wife (learning Czech).

No leagues, no streaks, just the high-frequency vocabulary needed for conversation.

Later I added couple of languages as requested by my friends. Its free, always will be free and non-commercial. It already has around 450 users which is exactly 447 users more than I thought it will ever get.

App: https://2000-words-app.vercel.app/login Tech: Typescript, Resend, Supabase, Vercel Languages: English, Czech, Spanish, Dutch, Portuguese (European), Japanese