The Google APIs Introduction kotlin for android development series describes the steps involved for enabling Google API’s, creating OAuth2 credentials and the kotlin code required for the android devices.
The Kotlin Android check Google Play Services availability development tutorial describes how to check if google play services are installed on your device.
The Kotlin Android Check Network Connection availability development tutorial describes how to check if you device has network connectivity.
The using Google Libraries for Android tutorial describes how to access the google developers libraries for your android application.
The Simplifying Runtime Permissions with EasyPermissions kotlin for android development tutorial describes how to use EasyPermissions.
The EasyPermissions library is a wrapper designed to simplify the usage of marshmallow and later runtime permissions.