I would actually argue that the web browser is not the correct place for web applications on mobile devices. "What?", I hear you say. I would go to the extra step of requiring the user to instal the app on their home screen, where the browser chrome is not visible. This way, the user is not confused with the back button problem, or the URL bar getting in the way of them using my app. An app is designed to be launched from the home screen, not the web browser which is designed for viewing web pages. The reason I almost never use mobile web apps is because they are too hard to launch compared to their native equivalents. I have to go to my web browser, type in a URL or choose a bookmark, hope I typed it right, wait for it to load from the server, etc. The competing native app or "installed web app" launches almost instantly with one tap on my home screen. Home screen web apps still have all the benefits of web applications, but they avoid some of the problems and feel more "app-like", or more like what the user is used to. This also allows us to create a more native looking and feeling interface that the user will have an easier time using because it is similar to what he knows.

I'm actually not even sure if the mobile web is ready for full-featured applications at all yet. The huge platform differences really make it a challenge to produce a good user interface across all of them. Mac, Windows, and Linux are similar enough to make it possible on the desktop, but the mobile user interfaces have not come together enough yet to make it possible on mobile. I think the current options are either to create native apps for each device or to create a web app with differing UIs according to the platform you are on in order to create the best user experience. I know a lot of people with disagree with me, and even I'm not entirely sure about this position, so convince me otherwise! :-)