I did not want to hear that you have no intention of getting the app in Amazon/Kindle platform. As a home with 6 Kindles and 3 Fire phones, I beg of you to reconsider getting into Amazon app. I tried sideloading Google services onto my HDX last year, and it caused more problems than it was worth.
How else will you integrate the Echo API into it, so I can just say " Alexa set the livingroom lights at 50% and lock the front door" and have it magically happen ? One of the main factors in getting the Echo, was the hope that somebody would link "her" voice recognition/command to a HA platform.