It's mostly used explicitly by GrapheneOS users. It's maintained by a supporting community member. Some strict security-focused users have been using it for a few years. I don't expect this to be the first choice app store for people due to how limited the app catalog is, but it is worth us mirroring on our App Store so users can get it quickly, and because it is the what we consider choice for security and privacy.

Future progress and adoption will hopefully change things