UPDATE: Angel has now also gone live on the Apple iBookstore, so it is now available for easy download to your iOS device: iPad, iPhone or iPod Touch.
And in further good news: this version is only $2.99 / £1.99 (a discount price set by the store itself! - Correct at time of writing)
ANGEL on the Apple iBookstore:
http://itunes.apple.com/book/angel/id540881828