CopperheadOS is a Linux-based mobile operating system with a focus on privacy and security. It builds on the latest stable release of the Android Open Source Project (11) which is Android without any Google apps and services.
CopperheadOS can run Android apps unless they have a hard dependency on Google services. It ships with the F-Droid app store to provide access to thousands of open source apps but it can also run many apps from the Amazon Appstore and Google Play Store.
Since it doesn’t include Google apps and services, CopperheadOS isn’t limited by the requirements imposed by Google for an operating system to be considered Android compatible.