Kotlin Android Extensions is an add-on package and plugin that make it effortless to find a specific View in your layout. Similar to ButterKnife you don't have to write findViewById all over the place. That really where the similarities end and where Android Extensions really make your code (and work life) better.
To get started you need to add these to your module's ("app" in many cases) build.gradle file.
apply plugin: 'kotlin-android-extensions'
Now in your Activity, Fragment, or View subclass you can start accessing the strongly typed views in just two lines.
// add an import import kotlinx.android.synthetic.main.YOUR_XML_LAYOUT_NAME.view.* // access the view tv.text = "Hello World!"
Thats it! There is no injecting, binding, or resetting anything. There is no casting. It's strongly typed so if it compiles, you won't get some runtime exception complaining about casting or a null pointer from a missing view.