Smart App Banners have been around since iOS 6 and are an easy way for websites to link to apps on the App Store. As app promotion methods go, these are intelligent and not as obtrusive as other methods.
To add them to your page you have to add a
First go to the page you want the banner to appear on and click on the gear icon to access the page's settings.
Now click on Advanced at the top right of the page and you'll be presented with a textarea where you can enter code to be injected into the page.
Next paste in the code below, replacing
XXX with your app's ID and
YYY with your iTunes affiliate ID (or leave it blank).