Great reference
While not that unique or beautiful, this app provides a universal app that has an easy to use dictionary with a good number of sample sentances, flash cards and kanji stroke order. A great reference on both ipad and iphone. It could use a bit of design love, but sticks to a native ios experience, which is pretty key to its ease of use.
I find the kanji handwriting recognition can be a bit hard to use for complex stroke orders that I am not as comfortable with writing, however it offers the more common radical lookup as well.
This app seems to have frequent updates and has been the best app of its kind on the apple store that i have found.
xabooth about
Midori (Japanese Dictionary), v1.6.3