Luxembourgish Studio — Speech-to-Text & Sproochentest Exam Prep App

The Challenge

Luxembourgish is a low-resource language with very few dedicated learning tools, and candidates preparing for the official Sproochentest proficiency exam had no mobile-first way to practice speaking and listening with immediate, accurate feedback. Existing language apps either didn't support Luxembourgish at all or treated it as a translation afterthought, leaving exam candidates to rely on static PDFs and generic audio recordings with no interactive practice loop.

Our Approach

We built the app around the national sproochmaschinn.lu speech engine, wrapping it in an exam-focused practice flow rather than a generic translator. Every feature was scoped against the actual structure of the Sproochentest — oral and written exercises, model answers, and playback — so learners rehearse in the same format they'll be tested in. We committed to a completely free, ad-free model to remove friction for exam candidates, and shipped a cross-platform React Native app to reach iOS and Android users from a single codebase, with optional account sync so progress carries across devices.

What We Built

A cross-platform React Native mobile app covering three core capabilities: Sproochentest Exercises with topic-based practice questions, example answers, and audio playback with autoplay; Speech-to-Text for high-accuracy transcription of recorded or uploaded Luxembourgish audio; and Text-to-Speech for natural-sounding playback of any Luxembourgish text. Answer recording and progress tracking are built in, with optional account sync to carry progress across devices. The app integrates directly with the sproochmaschinn.lu API for both transcription and synthesis, and ships completely free with no ads, subscriptions, or in-app purchases.

Results & Impact

Luxembourgish Studio is live on both the Apple App Store and Google Play, with support extending to iPhone, iPad, iPod touch, Apple Silicon Macs, and Apple Vision Pro. Version 1.1 introduced the full Sproochentest exercises section, rounding the app out into a complete exam-prep companion. The free, ad-free model was a deliberate choice to keep the app accessible to every exam candidate, regardless of budget.

Technologies Used