renative

Unified Development Platform for iOS, tvOS, Android, Android TV, Android Wear, Web, Tizen TV, Tizen Watch, Tizen Mobile, LG webOS, macOS/OSX, Windows, KaiOS, FirefoxOS Firefox TV platforms. Maintained by flexn-io on GitHub, where it has earned 1,948 stars from the community.

It's actively developed around android, android-tv, cross-platform, and is a solid reference for anyone building with these tools.