Google will give Android app developers until September 31, 2021 to adopt its in-app billing system for apps distributed on the Google Play Store. The same rules will apply to its own apps. The policy really only applies to less than 3% of developers with apps on Google Play. Google only collects a service fee if the developer charges users to download their app or they sell in-app digital items. Reports suggest the crackdown is aimed at Netflix and Spotify.