AI-Powered English Learning App

概 Project Overview

30

Test Users

7,800

Vocabulary Words

3

Learning Modules

A1-B2

CEFR Coverage

要 The Brief

Create a comprehensive English learning app for Japanese students that covers CEFR levels A1 to B2. The app needed AI-powered grading for writing and speaking, plus an interactive conversation feature.

Writing module with OCR extraction and AI auto-grading
Speaking module with Whisper transcription and evaluation
AI Conversation with CEFR level selection and real-time voice dialogue
7,800-word vocabulary database managed in MySQL

技 Tech Stack

Cross-platform mobile development with AI-powered language processing backend.

React Native Expo Express.js TypeScript MySQL Gemini API Auth0 Whisper

難 Challenges & Solutions

Consistent AI Grading

Ensuring AI provides systematic and consistent grading across different submissions while using appropriate vocabulary for each CEFR level.

Solution: Explicitly included the DB vocabulary list in prompts to achieve systematic and consistent grading. The AI generates practical feedback including specific corrections and common error pattern identification.

果 Results & Impact

Currently in closed beta testing at a learning academy with 30 active users.

30

Active test users

7,800

Vocabulary database words

3 Modules

Writing, Speaking, AI Chat

Closed Beta

Testing at learning academy

機 Key Features Delivered

Writing grading - OCR extracts handwritten English, AI auto-grades
Speaking evaluation - Whisper transcription with pronunciation feedback
AI Conversation - CEFR level selection with real-time voice dialogue
7,800-word vocabulary database in MySQL
Auth0 integration for secure user authentication

概 Project Overview

要 The Brief

技 Tech Stack

難 Challenges & Solutions

Consistent AI Grading

果 Results & Impact

30

7,800

3 Modules

Closed Beta

機 Key Features Delivered

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