I'm glad to see Kotlin making its proper debut. Android has been crying out for something a little more expressive and less verbose than Java, and Kotlin fits the bill perfectly.
Is that similar to Kotlin's buildSequence/yield/... implemented with coroutines? https://kotlinlang.org/api/latest/jvm/stdlib/kotlin.coroutin...
What I like about them both is that you can very often intuit how something is likely to work.
Kotlin + Anko makes Android development much less painful indeed.