Right now, I am building a separate app #nostr #safebox for the latter three capabilities (payment, sharing and storage).
But eventually my app could completely disappear into another app and become a set of #nostr network capabilities, so long as you have the private key to that instance of the capability (good practice to be a different private key), and the app code to support that capability.
The hypothetical example below, you would just add your #safebox private key and ‘Boom!’, you’re in business.
I don’t see this happening right away, but I can envision a world where everyone builds network capabilities and users incorporate into their apps and clients of choice.