perhaps one day we will have a scrivener for iPad application, although we perhaps should not hold our breath while waiting. What we can do in the meantime is to use one of four really good ways of connecting scrivener on the desktop or laptop to our writing on the iPad.
The iPad is a brilliant tool for writers, we can use it as a notebook when we are away from our desktop computer. No need for resorting to pen and paper, we can write our story this directly into the iPad using apps like Nebulous Notes and easily get that text into Scrivener on the Mac or even on Windows.