Running iPhone Webapps From the Home Screen Only

if (window.navigator.userAgent.indexOf('iPhone') != -1) {
	if (window.navigator.standalone == true) {
		// Initialize your app
	}else{
		// Display a message asking to add the app to the Home Screen
	}
}else{
	document.location.href = 'please-open-from-an-iphone.html';
}