That depends on what you mean by "widget" or by "APP".
If by "widget" you mean "app widget" (interactive element of a home screen), what you want is not possible, unless you write your own home screen application.
If by "widget" you mean "widget" (element of an activity, subclass of android.view.View
), you could create a custom subclass of WebView
that knows the URL to your gadget and arranges to load in whatever extra HTML/JS/CSS is necessary to display that gadget in a browser outside of iGoogle.
If by "APP" you mean "Android native application", you could look at PhoneGap. You would still need to identify whatever extra HTML/JS/CSS is necessary to display that gadget in a browser outside of iGoogle.