Here is my experience with the app store , I created a website for toddlers http://microangels.in , Someone suggested that I make an app, since I had the HTML and Javascript ready I used the android webbview and Jquery mobile to create the Toddler books app https://market.android.com/details?id=in.microangels . The app was released on February 10, As of today there have been 7951 installs with 68% active. I have integrated the app with admob and it has made $45 so far, I don't know if this is because kids tend to click on advertisements or its because the list scrolls below the screen and the clicks are accidental

My other app Taekwondo forms https://market.android.com/details?id=form.TaekwondoForm is webview based and released on Feb 25 , it has 532 downloads with 68% active installs and has made .83 cents so far.