According to Wizards.com:
You may have just heard about this announcement: DeNA is currently working on a D&D mobile game. Arena of War is a party-based battle game set within the Forgotten Realms—and it has a heavy emphasis on boss battles! Worldwide release is currently scheduled for late July.
Look for further news and information about this title on their site.
The game will be free and supported on both Apple products (Iphone and Ipad) and Android devices.
Should be cool.