Whether you’re new to Kotlin or bounce between so many languages that you need a quick reference (like me), I think you’ll find the Kotlin Cheat Sheet and Quick Reference at RayWenderlich.com handy! It covers the syntax that you’re most likely to use in day-to-day Kotlin development using clear — and in some cases, amusing — examples to help explain how to use various Kotlin features.
This is a revised edition: same content, improved layout. Best of all, you don’t have to be a RayWenderlich.com subscriber to get your hands on it. Check it out!
If you’d like to learn more about Kotlin and Android programming, be sure to check out RayWenderlich.com’s books, Kotlin Apprentice and Android Apprentice, two fantastic introductory books to the Kotlin programming language and Android development with Kotlin!