Yes. It just needs to follow the protocol; https://memo.cash/protocol
Where is stored my password? Who has the private key of my account balance at memo.cash? I think the protocol can display information but not replace memo.cash website.
It is stored on memo.cash (not on blockchain). I'm not entirely sure how it is stored. I'm guessing in a database encrypted and secured by your account password.
You can export your private key on the account page.
