Why am I unable to download videos from Amazon Instant Video?

A

AC Question

Amazon Instant Video

I have a Nook HD+ and I am a prime member, I got an email from Barnes and Noble saying that there is now an app for android to watch prime instant videos, however, when I try to download the app my Nook prompt comes up saying that they blocked the app from installing because its not a Google play store or Nook app. I am confused here......if the app is for Android devices and its available for download why won't my Nook let me download it? Any help would be appreciated.