JetBrains/anko - Pleasant Android application development.
JakeWharton/kotterknife - View injection library for Android.
pawegio/KAndroid - Kotlin library for Android.

TinyMission/kara - Web framework written in Kotlin.
jean79/yested - A Kotlin framework for building web applications in Javascript.

JetBrains/spek - A specification framework for Kotlin.

cheptsov/kotlin-nosql - NoSQL database query and access library for Kotlin.

ReactiveX/RxKotlin - RxJava bindings for Kotlin.
puniverse/quasar - Fibers, Channels and Actors for the JVM.
mplatvoet/kovenant - Kovenant. Promises for Kotlin.
klutter/klutter - A mix of random small libraries for Kotlin, the smallest reside here until big enough for their own repository.

antoniolg/Bandhook-Kotlin - A showcase music app for Android entirely written using Kotlin language.
damianpetla/kotlin-dagger-example - Example of Android project showing integration with Kotlin and Dagger 2.

ssoudan/ktSpringTest - Basic Spring Boot app in Kotlin.

JetBrains/swot - Identify email addresses or domains names that belong to colleges or universities. Help automate the process of approving or rejecting academic discounts.
IRus/kotlin-dev-proxy - Simple server for proxy requests and host static files written in Kotlin, Spark Java and Apache HttpClient.