Well you can obviously put can put your PDF on your iPAD via iBOOKs.
And I think you are able to downdown the Oracle eKit App for free ... whether thsi gives you anything with your existing PDF eKit I simply do not know. But you can try and report back.
I suspect Oracle will not upgrade your existing PDF eKit to a later eKit Plus.
I may be talking rubbish about all that. If I win the Euro-millions lotto I might buy an Oracle Training course, there again if I win the Euro-millions lotto I think I'll just eat Rasberry Pi. Others will know better.