Building the software that automates it all isn't hard, including the random number generation - and such an app could go on airgapped computers. It wouldn't be

Building the software that automates it all isn't hard, including the random number generation - and such an app could go on airgapped computers. It wouldn't be harder to use than a faucet. After the random part (not hard) it's just XOR, some of the simplest programming imaginable.