 
 
 this is snapchat 
. It will say whether you have installed 
, then it is directly OPEN 
. If you have it, you will download 
 questions. How can this technology 
 be implemented? 
I have found that it seems to be this tag
<meta property="al:ios:url" content="https://itunes.apple.com/tw/app/id12xx" />
<meta property="al:ios:app_store_id" content="12xx" />
<meta property="al:ios:app_name" content="xxx" />
<meta property="al:iphone:url" content="https://itunes.apple.com/tw/app/id12xx" />
<meta property="al:iphone:app_store_id" content="12xx" />
<meta property="al:iphone:app_name" content="xxx" />
<meta property="al:web:url" content="https://itunes.apple.com/tw/app/id12xx" />
<meta property="al:web:should_fallback" content="false" />but I find it doesn"t seem to work?
