Nielsen concludes “Ideally, the next step is to user test the redesign. You can do this with paper prototyping, so you don't have to fully implement a new app . . .”

Rather than that, it's actually quite easy (and overlooked IMO) to implement a meaningful A/B framework within iOS by setting up your experiments as live web pages that the app accesses.

The key reason NOT to do this is latency, so make sure you're on the fastest box possible and consider pre-caching the experiment images via SDWebImage or similar.

In our experience any loss you have around latency will be made up in spades by having an engine that lets you test your funnel in a real world environment.

ref for image pre-loading -

https://github.com/rs/SDWebImage

http://stackoverflow.com/questions/4617424/improve-uitablevi...

http://www.iphonedevsdk.com/forum/iphone-sdk-tutorials/13315...