When I download an eBook with format .epub, my N7 offers choices of apps to use for opening it, but none of the choices are any good. How can I make it open in Barnes and Noble Nook? (or will Google Play Books work? -- how could I make this app open the epub file?) So far, I have been moving the downloaded file to the Nook folder, after which I can easily read it in Nook, but that is not a very convenient way to do it.