Whilst I have made some beer money from the iPhone app (I get about $4 per copy sold), I worked out that I would have been better off flipping burgers at McDonalds for time invested. And the iPhone market is pretty big. However this doesn't worry me as I love doing it as a hobby/side business to work.
If a NAIPS app is out the question for now what about something to organise and read the AsA publications? If you already have the pdf files and databases for use with ozrunways isn't that most of the hard work done. Now you would just require a file download and manager.