The app on your iOS-enabled phone is available for download here through the Apple store.
It is also available for Android phones here.
Check out some images from Hearthstone for your phone!
As you can see, there were some UI changes implemented for the mobile interface. Tapping on your hand makes it larger so it's easier to pick cards to play for your turn. Cards are drag and drop, like the tablet version.
Hearthstone® is now playable on iOS® and Android™ phones! Featuring an all-new intuitive interface hand-crafted for the mobile experience, it’s easier than ever to take Hearthstone with you anywhere YOU want to play. Whether you’re cozying up for some “me time” or carousing at a Fireside Gathering with friends, relaxing at home or embarking on a grand adventure, the fun of Hearthstone is always at your fingertips.
Never played Hearthstone? No problem! Just download the app and run through a few lighthearted tutorial missions to get a handle on the basics of this quick and fun collectible card game. Before you know it, you’ll be slinging cards as your favorite hero in Play Mode against friends and other players alike. Soon, you’ll be on your way to earning card packs, in-game gold, and arcane dust as you command a colorful cast of characters into the fray.
Already playing Hearthstone? Your card collection and progress are shared across any device that you use to play the game. That means all the cards you’ve collected will be waiting for you whenever you enjoy Hearthstone on your mobile phone.
There’s more! Whether you’re a neophyte who has just completed the fun introductory missions or a seasoned veteran, if this will be your first time playing Hearthstone on your iOS or Android phone, then as an added bonus for going mobile you’ll earn a free Classic card pack just by playing a game of Hearthstone in Play, Arena, or Practice mode.
http://itunes.apple.com/app/hearthstone-heroes-warcraft/id625257520?mt=8" target="_blank">iTunes®https://play.google.com/store/apps/details?id=com.blizzard.wtcg.hearthstone&hl=en" target="_blank">Google Playhttp://www.amazon.com/Blizzard-Entertainment-Hearthstone-Heroes-Warcraft/dp/B00P77ZAN8" target="_blank">Amazon App Store
Hearthstone requires an Internet connection to play. Getting started is quick and easy! Download Hearthstone now from the http://itunes.apple.com/app/hearthstone-heroes-warcraft/id625257520?mt=8" target="_blank">iTunes® App Store?, https://play.google.com/store/apps/details?id=com.blizzard.wtcg.hearthstone&hl=en" target="_blank">Google Play, or the http://www.amazon.com/Blizzard-Entertainment-Hearthstone-Heroes-Warcraft/dp/B00P77ZAN8" target="_blank">Amazon App Store to start building a deck of your own today.
Have an older smartphone? https://us.battle.net/support/en/article/hearthstone-system-requirements" target="_blank">Check here to see if your device meets the minimum requirements.
If you’re new to Hearthstone, visit our http://us.battle.net/hearthstone/en/forum/topic/12034043452" target="_blank">New Player forum for help getting started. Also, don’t forget to like Hearthstone on https://www.facebook.com/Hearthstone" target="_blank">Facebook and follow us on https://twitter.com/playhearthstone">Twitter for all the latest news and updates.