Google Play Billing Library 1.0 has been released to simplify billing, allowing you to focus your efforts on implementing logic specific to your app, such as displaying in-app products and purchasing items. This library includes several convenience classes and features for you to use when integrating your Android apps with the In-app Billing service.
Starting with Play Billing Library Developer 1.0 release in September 2017, the minimum supported API level is Android 2.2 (API level 8), and the minimum supported In-app Billing API is version 3.
For more details about this launch, checkout our blog post “Money made easily with the new Play Billing Library”: goo.gl/fEBJ5c
Subscribe to the Android Developers channel here: goo.gl/vLYDU