Not sure if this is the right place to post this, but I managed to get Umineko along with the WH patch to work on my iPhone/iPod Touch. I've only tested it with EP 4 but there's no reason why it wouldn't work with the other EPs.
The hardest part with getting this to work completely was to build a working version of onscripter-en for iPhone, which I did (although with a quite old version, I couldn't get newer versions onscripter-en to work).
I'm going to release this build and a tutorial soon after I test more stuff and after my exams.
Here are some screenshots:
Check out my blog for more info and other VN's on iDevices.