I hope by epub you mean DPS folio publication. You will need renditions to target diferrent devices screen resolution. You will need to publish different versions of folios and the viewer app will know which folio to pick it up according to the screen resolution of that device. For more help on folio renditions go here http://help.adobe.com/en_US/digitalpubsuite/using/WS9293e1fb3b977c5c-2337961812e35738f56-8 000.html
I would not like the book to come with the dps viewer app (I am using it for other things of course).
I want it to be a standalone app that I can publish on Apple iBooks
Then you’re in the wrong forum. iBooks uses the epub format.
Check in the InDesign forum.