ePub and PDF for sure.
I was given a gift card to Barnes and Noble, but I have the Kindle Fire. I was wondering if I could download the book on the computer and add it to the Kindle, but I need to know if it would have a supported file type or not. So my question is, what file extensions are NOOK Books?
And in an unrelated question, why doesn't Amazon have ALL the apps from the Android market? Isn't it supposed to, or does it not?