...microG
A free-as-in-freedom re-implementation of Google’s proprietary Android user space apps and libraries, enabling the use of every Google service you need without keeping another closed-source binary blob in your Android system.
The F-Droid App store
An installable catalogue of FOSS (Free and Open Source Software) applications for the Android platform. You can use it to access plenty of FOSS applications or even the Play Store via Aurora Store.