This sounds like a tough one, but I'm sure others have faced this dilemma. I'd like to develop a solution that is identical for iPhone, Android and web sites. A user accessing my solution from their smart phone or from their PC / Mac using Firefox, Safari, Chrome etc. would have precisely the same user experience.

I think the standard way to do that today would be to develop a web app (HTML 5, Javascript) with the device constraints / form factor in mind, then test across all device and browser versions.

It would be really lovely if it could be done a different way -- develop in Corona, and deploy on the web in a suitable framework or container that makes the very same Corona solution available in the browser. Note this would NOT mean an iPhone or Android simulator in the browser, but rather the same screens, flows etc. in the browser.

Has anyone solved this problem?

There is currently no solution which allows native iOS and Android and Apps and Web.

Most cross platforms toolkits are bound to the lowest common denominator, so the more platforms, less things you can do.

Corona SDK supports android and iOS and does so quite well