Twitter app card not working



I’m using our website and have embedded the following code on this page:

Twitter card

<meta name="twitter:card" content="app">
<meta name="twitter:site" content="@UltimateFanLive">
<meta name="twitter:description" content="Experience the new way of watching live football with real-time fantasy football. Join the action and play with fellow football fans all over the world during every live EPL, UCL & La Liga game.">
<meta name="twitter:app:country" content="GB">
<meta name="twitter:app:name:iphone" content="Ultimate Fan Live - Real-time Fantasy Football">
<meta name="twitter:app:id:iphone" content="884509638">
<meta name="twitter:app:url:iphone" content="">
<meta name="twitter:app:name:ipad" content="Ultimate Fan Live - Real-time Fantasy Football">
<meta name="twitter:app:id:ipad" content="884509638">
<meta name="twitter:app:url:ipad" content="">
<meta name="twitter:app:name:googleplay" content="Ultimate Fan Live">
<meta name="twitter:app:id:googleplay" content="com.ultimatefanlive.ultimatefanandroid">
<meta name="twitter:app:url:googleplay" content="">

However, it’s not working, do you know what we may be doing wrong?