HTML5 Cache manifest - will this work?

Question

This is what I want to do:

LOGIN SCREEN -> WEB APP

Login screen asks for credentials which are checked against a database live. If credentials are valid, go to the web app.

Web app: has cache manifest. So if the user passes the log in screen, they will never have to log in again. They can add the web app link to their homescreen and continue to go straight to the web app, even if they are offline, forever after.

The caveat: I don't want unauthenticated users to ever get to the web app screen, hence that first initial log in. But once that's done, I want the user to be able to cache the web app page.

Does this sound possible or am I wasting my time attempting it?

Answer 1

No, that actually sounds like it can be done! Also doesn't sound that complicated.