I don't have an I-pad but do have an android tablet. I have done some work on a different set of rules. Impetus a Historical Ancients set. I setup an interactive QR sheet in html have a look at that, it may give you guys some ideas.
http://www.mkparsons.eclipse.co.uk/IGAP.zip
What I'm currently thinking about is some form of interactive fleet list for SFO which you check of the hull boxes. Probably using Adobe forms or some such.
If you produce a full blown app for the I-Pad then you are limiting its appeal and need to make a significant commitment to getting Apples approval to put it on the Apps store, but if you do HTML or Forms based stuff more people can use it and you do not need to jump through any of Apples loops.