It becomes much easier over time. I'm at a point where I could certainly accomplish this, especially now with great projects like CocoaPods. Experienced web developers can create a simple CMS lightyears faster than I can, its all relative.
Now what I find most interesting is that the author doesn't seem to have a large portfolio of apps. The "More by this Developer" link only shows this app, while his website only points to Discovr (http://discovr.info/) which I can't imagine he's the only developer for. I'd be curious to learn more about his expertise.
From experience, if you stick with standard UIKIt navigation schemes (i.e. use nav bars not FB/Twitter style pop-unders) and, critically, standard Apple approved color schemes (i.e., light not dark UI elements) then crafting an app within Storyboard is incredibly straightforward, especially if you consider PaaS solutions like Parse.com integration[1]. The problem seems to be managing the complexities of non-standard UI elements.
For what it's worth, Jony Ive seems to be pushing us to all adopt the design approach of the OP. Wonder if 'deference to content' will become the new normal?
I actually prefer doing all of the design and drawing myself and avoid things like NIBs and Storyboard. It's not really difficult, just takes time to absorb all that there is because there is so much customization you can do. And watch out for iOS 7, especially with animations, there are loads of new options.
Now what I find most interesting is that the author doesn't seem to have a large portfolio of apps. The "More by this Developer" link only shows this app, while his website only points to Discovr (http://discovr.info/) which I can't imagine he's the only developer for. I'd be curious to learn more about his expertise.