See here for what's probably the best instruction page on how to do exactly that:
http://intelnav.50webs.com/app_project.html
It's based on a Webview, that is it opens the page and does all the navigation in the app window, not in the default browser. So if you want to open it in the browser, you have to use Intent, as said in previous answers.
My 2 pennies worth, I think it's better in the app window unless you really want complex navigation with the possibility of opening additional tabs, windows and so on. The drawback with the external browser is that, as far as I could see, there's no way to tell if the page is already open in the browser so you'll launch a different copy (in a new tab) every time. If the user doesn't close the tab at the end, they usually don't, it can become quite annoying. Besides, within an app you'll probably have somewhat better possibilities for ads should you ever want them.
Versus a simple home-screen bookmark, as others pointed out, it's simpler and more convenient for end users to just download an app from an online store (usually Google Play). It's what they're used to do. And they do have a lot of additional info available, like what it does, what others say about it, screen shots (if you provide some for them but you should). Plus a way to comment / complain themselves. It's a different thing. Technically it may not make a lot of sense but from a simple user's perspective it's clearly better IMO.