I was playing around today with an app for the iPhone I bought from the Apple Store for $1.99. It's called Pro HDR X. It creates HDR images in your iPhone. I'm thinking it must take more than one shot, as you'll see a bit of ghosting in one of these images. It seems to work pretty well in extremely difficult situations, though.
Here I was standing in dark shadow shooting into the sun with the sun just barely behind the edge of the building. This is untouched out of my iPhone. Pretty impressive dynamic range.
This shot shows some ghosting in the trees and the legs of the students passing by, and it didn't handle the sky very well (created some noise), but the range isn't bad.
And here's another where I was in very dark shadows. No ghosting here, but nice dynamic range.
Not bad for a $2 app.