Actually apps like this are the one time I'm somewhat okay with the browser stopping me from navigating back at all (hopefully while displaying a dialog telling

Actually apps like this are the one time I'm somewhat okay with the browser stopping me from navigating back at all (hopefully while displaying a dialog telling me work will be lost if I back out and giving me a confirm option), though ideally it would just save everything always like Google Docs does so then it just doesn't matter as much.