Ahhh, even more useful info Scott. Never would have known this and maybe explains why there was no "key" I could find.

I finally got an email response to my query about whether I had to buy a Key for each device - and they said they it is good across the same platform android or ios IF purchased directly from them or the android app store. Now I know why they didn't mention the amazon app purchase and why I can't find a key (at least I think I understand).