It actually works really well in IntelliJ Community Edition. There is a template for creating a new Kotlin/Native project, the auto-completion works and there is even unit testing support! Things have come a long way since the early days of compiling your own cinterop stubs and figuring out APIs from the generated wrappers. :)

If you want a debugger you need CLion, though. And the compiler is really, really slow – but they seem to be working on benchmarking things recently, so presumably it will be improved.