[loumf]

ReactNative does not render to web views. It uses web development constructs like CSS, Flexbox, and JavaScript, but the output is the native view hierarchy. Facebook is using it (in Paper, at least)

FaceBook thinks you should use ReactNative for mobile and React for the web -- they call it learn-once-write-anywhere -- the UI code is not portable and that is not a goal of the project.

The only things I know about where you can run in a browser and in a native app are HTML-based and use app-wrapped web-views on mobile. I would look at jQueryMobile and Ionic if you want to go this route. You wrap either in Cordova/PhoneGap.