React Native Component Kit
"UI Kitten is a React Native UI library that allows you creating stunning multi-brand cross-platform mobile applications. The library is based on Eva Design System which brings consistency and scalability in the design and development process.
It contains a set of general purpose UI components styled in a similar way. And the most awesome thing: the themes can be changed in the runtime, with no need to reload the application.
It's 100% free and open-source!"