Pooleys iPlates
 

...Just released for the iPad £39.99 - Really! When the printed spiral bound version is £26.99, plus, there's no guarantee it won't crash every five seconds like most apps in their early days!!

You can save the Plates you need on an Ipad for free using the AIS app, :ok:

Cost of iPlates
 

Well if you do the maths..... The digital version becomes Vatable like all ebooks or apps. So there is 20% apple take 30% so that's 50% before any development costs which are also expensive. So I found it quite reasonable and it works well. I bet it costs them more than printing a book and sending out amendments.

Also if you look at Jeppesen alternatives, it very good value.