Right, I imagine most people will not run their own servers. At least today. But as that get's easier, I'm optimistic that will change. For now, in the context of Standard Notes, early adopters will run their own servers, but I imagine others would just pay for a shared hosting service. Which isn't perfect, but the content will be encrypted locally so the privacy concerns are somewhat mitigated.

Android client would be convenient. I'm pretty close to finalizing a first release of the spec. Then I'm going to start on the iOS client.

Any contributions you make could accelerate progress on the spec substantially. Follow the mailing list on https://standardnotes.org or follow for updates on Twitter @standardnotes. If you're serious about building a client, shoot me a message @bitario.