The only use of blockchain in this app is the username creation. And that is pretty much hidden from the user experience.

Is the system able to be used privately on networks without Internet access? I think offline use is mandatory (think: RasPi LAN party in Kenya).

I’m approaching this space in another way (search: “iSpooge Live”). I have an RSS/ActivityPub-like feed and reader pair, with network address as identity, generated statically and exposed via CDN w/ long cache TTLs. Sovereignty is the m.o. of the stack.

Graphite Publishing supports offline storage (not yet implemented but will be soon). But some level of network connectivity is required to at least create your username and sign in for the first time. After that, network connectivity is not necessary (after the offline storage feature is released.

Great question!