Kotlin

• Reference
• Kotlin Playground: Edit, Run, Share Kotlin Code Online

Learn

• Tutorials
• Kotlin Koans: The Best Way To Learn Kotlin for Java Developers
• Kotlin for Android Developers - Udacity
• Build Your First Android App in Kotlin

Android

• Kotlin for Android
• Kotlin and Android  -  Android Developers
• Kotlin Android Extensions
• Kotlin/anko: Pleasant Android application development
• RecyclerView and Kotlin

Sample Apps

• Samples apps
• Introducing Android Sunflower – Android Developers – Medium

Material Design

RetroFit

• Supercharging Retrofit with Kotlin – The Coinbase Blog

Dagger

• Android Frameworks Using Annotation Processing
• kotlin-examples/gradle/kotlin-dagger at master · JetBrains/kotlin-examples

Kotlin Android Extensions

build.gradle

apply plugin: 'kotlin-android-extensions'

Parcelable

import kotlinx.android.parcel.Parcelize

@Parcelize
class User(val firstName: String, val lastName: String, val age: Int): Parcelable