While working on a React Native app, I needed to enable communication between two phones, one running Android OS and the other running iOS. Although the phones could communicate, at the time there was no React Native solution. So I decided to simplify things and create a React Native library for this exact purpose.
I wrote code in Kotlin and Swift, wrapping minimum native Android and iOS BLE functionality in a cross-compatible API for React Native. Then on the React Native side, in the true "learn once, write anywhere" fashion, I used the API I exposed with Typescript and ran it on both Android and iOS devices.