Smart Translate — WearOS Translator
Quick on-wrist translation with a delightful, glanceable UI and voice input. It employs the best speech recognition system on the market.
Project Overview & Innovation Report
Executive Summary
Smart Translate is a Wear OS app that turns your watch into an on-wrist speech and text translator. It records speech on the device, sends it to a secure backend for transcription and translation using the latest AI models, and presents results with a simple and elegant UI. Users can choose the output language. The input language is intelligently detected. Review recent history, and play back translations using on-device Text-to-Speech.
Key Innovations
- 🚀Hybrid processing pipeline with on-device capture and backend translation
- 🚀Dual input modes with microphone recording and system text overlay
- 🚀On-watch TTS playback for excellent performance
- 🚀Persistent preferences and history with lightweight storage
- 🚀Wear-optimized UI using ScalingLazyColumn and Compose for Wear
🚀 Core Learning Modes & Features
Voice Mode - Speak and Translate
Capture speech directly on the watch using MediaRecorder, process through secure backend, and display translations with comprehensive state handling.
Highlights:
- ✓AAC/MP4 recording
- ✓Robust state machine: Idle, Recording, Processing, Translated, Error
- ✓Upload to backend with error handling and cleanup
- ✓Real-time UI feedback during all phases
Text Mode - Keyboard/Overlay Input
Text input with predictions using the Wear OS system overlay
Highlights:
- ✓Fast and context-aware predictions
- ✓Great for a quick translation in silence environments
- ✓Easily swtich back to voice mode with 3 taps
History & Settings Management
Check the recent translations, with persistent storage on the device. Clear them at any time.
Highlights:
- ✓Store the recent translations on the device
- ✓History persists even after device reboot
- ✓Clear history at any time
Audio & TTS Playback
Play back the translations using on-device Text-to-Speech. The language is automatically detected.
Highlights:
- ✓Fast as it needs no network access
- ✓Graceful handling of unsupported languages
🤖 Backend Integration & Performance
Smart Translate captures audio on-device and sends it to a secure backend for processing. Processing time is usually 1-3 seconds. It uses Edge Functions to use the closest server to the user. The backend is rate limited to prevent abuse.
How It Works
- 🔹Uses the latest AI models from OpenAI, but can be easily replaced or updated
- 🔹Uses Edge Functions to reduce latency
- 🔹Has generous but safe data limits
🛠 Technology Stack
Wear OS
Jetpack Compose for Wear with Material3
Kotlin
Version 1.9.x with Java 17 target
OkHttp
Multipart uploads and JSON networking
TTS & Audio
MediaRecorder and TextToSpeech APIs
💡 Why It Matters
Smart Translate focuses on speed, simplicity, and reliability for on-wrist translation. With a clear state model, resilient audio and network handling, and a Wear-first UI, it delivers a practical translation companion that minimizes friction in travel and daily interactions.