In the world of Android, findViewById() is the necessity. And we know how painful it is to code it every time for every view. Yes, a butter knife will give some relief, but it has its own disadvantages (we will not go into them). Since Kotlin is targeting for Android app development, it has to provide the solution to this problem. And Kotlin's kotlin-android-extensions is the solution.
If the following is your view:
<com.twitter.sdk.android.core.identity.TwitterLoginButton android:id="@+id/loginWithTwitter" android:layout_width="wrap_content" android:layout_height="wrap_content" />
A typical Java code would look as follows:
TwitterLoginButton loginWithTwitter = (TwitterLoginButton) findViewById(R.id.loginWithTwitter); ...