Open Source Kotlin Text to Speech Software

tts-server-android is an Android system TTS application that acts both as a powerful local text-to-speech engine and as a flexible TTS “server” for other apps via HTTP. It includes a built-in Microsoft TTS demo interface and lets users configure custom HTTP requests, making it possible to route TTS through various cloud providers or local servers. The app can import other local TTS engines, giving Android devices a unified interface to multiple voices and providers, and it features simple narration/dialogue detection based on Chinese quotation marks so it can read text with different styles for narration and dialogue. It is built with Kotlin and Jetpack Compose, and the project is structured into multiple libraries (lib-tts, lib-server, lib-compose, lib-database, etc.) to separate UI, server logic, and TTS handling. The app supports advanced features like automatic retry, fallback configurations, text replacement rules, and integrations with reading apps.

Dicio is a free and open source voice assistant for Android that focuses on strong privacy by running its understanding and response generation directly on the device whenever possible. It supports multiple input and output methods, including hotword-based voice input using the Vosk speech-to-text engine and a graphical interface for users who prefer to tap instead of talk. The assistant is built around a flexible “skills” system that lets it respond to a wide variety of requests such as search, weather, navigation, calculator, timers, media control, and more. It offers rich multilingual support and is already available in a wide range of languages including English, Spanish, German, French, Italian, Russian, and others. The project integrates tightly with a custom “sentences language” and compiler so each language can define its own natural phrasings to trigger skills without sacrificing accuracy.