I tried again on the iPad, this time I followed the instructions!
It does work on the iPad if you download it from the iPad, having said that, I do not think anyone would describe it as a true 'App', it seems more like an ordinary link. Actually although I just said it works, I used that term pretty loosely as the best view I can get only allows me to see the top half of the magazine pages with any clarity.
I tried the same method of installing it on my Android phone, and from there it does not work.
Ian P