Difference between this version and the premier version – PDF Max Pro Review

I like this app but needs the extra options available in the premier version. this version (the pro)offers upgrade to premier version for $0.99 per week (or around $48 per year), the premier version is offered at $9.99 one time purchase. what is the difference between the premier version offered as stand alone app (for one time payment of $9.99) and the upgraded one from the pro version ($48 annually)?
Review by ITfuture on PDF Max Pro.