Which smartphone do you own? Make an app that you would use on that phone. You can try going the native route, but if you are familiar with JS/CSS, I would sug

Which smartphone do you own? Make an app that you would use on that phone. You can try going the native route, but if you are familiar with JS/CSS, I would suggest looking at PhoneGap. That way, after you ship to one store, you can more easily prepare your app to be shipped to the other store. Good luck!