I answer a question at a forum on creating a Android application where it would only use a webview to invoke a web application, I imagine that this is possible, because this way I can get on the android market one application to use my
web application. I gave them Basic4android to develop it, I hope this can be done, Is this possible with webview?. If you want I can send you the forum post link for more clear.
You can use Webview to show a specific page and make it appear as a native application. However if you are using Basic4android you will get better results by building a true native application.