With iOS6, you can easily add a meta tag to your website which automatically creates a Smart App Banner to the top of the webpage when viewed on iOS Devices.
To do this you need to add a simple meta tag to your website to create the App Banner. Here’s the code:
<meta name="apple-itunes-app" content="app-id=615938359">
The App-ID the minimal amount of information you need. The button will show open if the user has downloaded it, or
You can get Your App ID from your Apple App Store link.
The App ID is 615938359.
If you have an affiliate account, and/or want the button to go to a specific view in your app, there are advanced tags you can add: