Would there be a way to make such clients easy to use?
It sounds like a lot of work?
Theoretically, you could create an install that installs a local full node & webserver and a copy of the memo.cash site, & you'd just access it with a browser on your local machine.
True, although doing so would demand storing the entirety of the blockchain and well, running a node. It's not practical for mobile or casual users.
You should be able to use bloom filters so you don't have to download the entire blockchain.
