I have enjoyed reading all the replies to this thread. Much to learn! I bought and downloaded calibre companion directly from the amazon store and it works like a champ! I sideloaded moon + reader from my galaxy 8. I think it was also downloaded the from amazon store....I played around with it so much that now I am not sure which store it came from
. But I have the free version, not the pro as I had thought. What would be the advantages of the paid version over the free? If it is definitely better, then buying it would be a good investment in my HDX which I plan to use for quite a while!!