Is there an open source Android app project that’s well-written in Kotlin and well-structured? I’m looking for a good example project to send to a development team and say “that’s the type of structure and quality we’re aiming for”.

You can check out Google's architecture sample. That's quite nicely written. Infact I'm using it as a guideline for setting up project with CLEAN https://github.com/android/architecture-samples.git

Thanks, that’s a good start!

I don't now if helps but @Madalin Valceleanu publish an interesting repo in #feed channel, this is the link https://github.com/VMadalin/kotlin-sample-app