How can I create an iOS webapp that returns to the previous state after being inactive?

When I create an iOS webapp in HTML, I use following code:

<meta name="apple-mobile-web-app-capable" content="yes" />

So, after adding it as a Safari bookmark to the home screen of the iPhone and starting it, I noticed that once I go back to the home screen and re-open the app, the web app doesn't keep its previous state.

It doesn't start where I left of and opens the start page instead. Native apps don't do that.

How can I create an iOS webapp that returns to the previous state after being inactive?