Local Speaking Coach PWA

Let language learners chat, shadow, and score with their own API keys in a local PWA

Problem

People who want to practice spoken German and other languages find that paid apps are mostly wrapper apps around off-the-shelf LLM and speech APIs with a few preset scenarios. For beginners, what actually matters is overcoming the fear of speaking and getting detailed pronunciation correction, yet existing tools are either expensive or send data to the cloud.

Solution

A pure static PWA where users plug in their own LLM API and speech assessment key, then do multilingual AI chat, generate native-speaker audio, record shadowing, and receive pronunciation scores. All keys, chat history, and recordings stay in local IndexedDB and never leave the device.

Users

Language learners who want speaking practice, care about privacy, and are willing to bring their own API keys

MVP

Multilingual AI chat page; one-click TTS native sample audio; recording and pronunciation scoring integration; local IndexedDB storage for everything; UI in 10+ languages.

Revenue

Open-source core is free; paid hosted version or one-time purchase to remove ads and unlock preset scenario packs

Why now

LLM and speech API costs keep dropping, free tiers like Azure Speech are generous, and users increasingly accept local-first, bring-your-own-key tools