Apple Watch Functionality - Swift vs. RN

Which sorts of Apple Watch functionality would require a Swift build, as opposed to a React Native one?

Thanks, in advance!

The short answer is, “all of it.” Our Apple Watch scaffold uses Swift, not React Native.

We don’t recommend building an Apple Watch app in React Native; this is a nonstandard/experimental approach that wouldn’t be suitable for a production setting.

If you’re doing a mobile and watch app, then you could certainly build the mobile app in RN and the watch app in Swift.