Originally Posted by PeterT
Are you sure it is the same file on both platforms? Remember, if you read a book in Kobo ePub format (kePub) on any platform you will see page number per chapter. However, reading an ePub format shows page number per book.
AFAIK the iOS App reads kePubs NOT ePubs.
The iOS App will read ePubs. It's a bit fiddly but iTunes can handle the transfer. With device connected, go to 'Apps' on the devices screen, scroll down to 'File Sharing'. The Kobo App should appear on the left side. Highlight it, then click on 'Add' at the bottom of the page. Select the ePubs you want to transfer from the directory you have them in and they will transfer over and appear in the Kobo library.