I have been waiting for Mr Tides to be ported to the iPod/iPhone! There are a couple of free tide apps, but they require online access, while Aye Tides has its own algorithm and is independent of outside support access, making it much more useful in all the remote places boaters go. I had a bit of trouble figuring out how to access the graph view until I went back to the iTunes Store and reread the description of the features. Duh! Turn it sideways! That had not occurred to me. You might want to incorporate that info into the About text.
Merriwake about AyeTides