This promotion has now ended! You can still grab our book at O'Reilly's site.
The newest book (released December 2012) by Jon Manning and Paris Buttfield-Addison, co-founders of Secret Lab, is currently on sale from O'Reilly! Our book, along with a collection of other great iOS-development books, is available in the Build Successful iOS Apps sale.
You can use the discount code WKPRGS6 or visit http://go.secretlab.co/OELh to get 50% off.