Charla — conversation-first Spanish

#Problem

I'm on Erasmus in Alcalá de Henares and wanted an app that teaches the Spanish I actually hear, not word lists. It also had to show both variants: Latin American Spanish first, and the Spain version right next to it.

#What it does

• Course A1 → B1: a placement check, then lessons built around a dialogue with audio, 8–12 new words, a short grammar point and 5–8 exercises.
• 548 words in 10 topics with pictures, gender-coloured articles and examples. A daily spaced-repetition review and six practice modes (picture → word, listening, typing, flashcards, memory…).
• One variant setting 🌎 / 🇪🇸 drives words, dialogues and voices. Answers in the other variant are accepted and explained.
• Progress saves after every exercise and syncs between phone and laptop, even after working offline.

#How

• React + Vite + TypeScript + Tailwind, mobile-first.
• Firebase free plan: Authentication plus Firestore with offline persistence. Security rules are tested with the emulators.
• Audio via the browser's Web Speech API. No paid APIs, no AI at runtime.
• A vocabulary validator runs before every build, so broken data never ships.