Twitter app card not working

ios
android

#1

I’m using our website and have embedded the following code on this page: http://www.ultimatefanlive.com

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="https://itunes.apple.com/gb/app/ultimate-fan-live-real-time/id884509638?mt=8">
<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="https://itunes.apple.com/gb/app/ultimate-fan-live-real-time/id884509638?mt=8">
<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="https://play.google.com/store/apps/details?id=com.ultimatefanlive.ultimatefanandroid">

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

Thanks!