I highly recommend Obtainium. It is a great way of installing and updating applications onto your Android phone. Instead of being a central store, you add the source for each project (from Github, Gitlab, Codeberg, etc) for the applications you use. It is the only "store" I added on my GrapheneOS phone. It allows absolute granular control of what I choose to install from the source; true digital intentional-ism.
Main: https://obtainium.imranr.dev/
Source: https://github.com/ImranR98/Obtainium
Also, here is a list of "complex applications" to make it easier to add them to Obtainium: https://apps.obtainium.imranr.dev/