That's a different use case. A client side web app is supposed to mimic the use case for native apps. While sandstorm seem to mimic the use case for Web Apps. I

That's a different use case. A client side web app is supposed to mimic the use case for native apps. While sandstorm seem to mimic the use case for Web Apps. If you are the only user I guess you could try to port it as a Chrome App, but Sandstorm seems to be aiming for something available online to be accessed by multiple users.