Hello,
I just updated the iPhone app to 2.1.5 and my reading plans are still not updating correctly. If you don't miss a day, the updating works beautifully. Once you fall behind and use the "adjust plan from today" feature in the desktop, the date does not update correctly on the iPhone. I reported this awhile ago and was hoping that this would be addressed in the next update (which was released today), but it was not.