Works with any cell provider.

Graphene is a privacy hardened operating system. The website has lots of info on motivation and use case. I imagine it like a zoo where the apps are all kept in cages and visitors come through a ticket gate.

Combine that 'taming' with a foss-first mindset and you're well on the way.

I haven't yet been down the silent.link and friends rabbit hole, but that's probably the next step.