This is a Universal Binary application, meaning it runs natively on all iOS devices. You can 

create compelling real time pre-visualizations and storyboards of your ideas on your iPad, iPhone or iPod touch with Storyboard Composer HD. Storyboard Composer HD is the world’s first mobile storyboarding app which allows you to storyboard where you need to when you need to. Simply take a photo, drop in characters, add camera or scene direction, then play the project back in real time. 
 This app retails for $14.99/£9.99/Download here