There is what appears to be a UIPickerView in this app. Did the developer re-implement this in HTML5? If so, doesn't that defeat the purpose of using HTML5 if they're just going to replicate iOS's look and feel?
And more importantly, why is this on the App Store if it's HTML5? I'd like to see this running 100% in the browser and then compare vs. native app.
I actually think the app is pretty well made; I didn't notice too many of the problems that the other people are critiquing when viewed on my iPhone 5.
Having said that, the bigger question is: why do all that custom work when you can make a native one much quicker and more easily?
I think what this app shows is the lack of a HTML5 framework to quickly put together mobile apps that feel native the way you can with the iOS SDK or Android SDK. In the HTML5 world there are a lot of frameworks and libraries to create a mobile website, but there isn't one that lets you make a native-feeling web app. There are a lot of disparate pieces addressing different issues (PhoneGap/Titanium for native app launching, Bootstrap/Foundation for UI controls, fastclick implementation for faster tap response times, removing the URL header, hiding browser scroll bars, ...).
And more importantly, why is this on the App Store if it's HTML5? I'd like to see this running 100% in the browser and then compare vs. native app.