This is limited to Fire OS.

"The Amazon Maps API is a programming interface that enables you to add mapping capabilities to your app on Fire phone and most Fire tablets."

"The Amazon Maps API v2 is compatible with Fire OS 4.5.1 and higher, which is available on 3rd and 4th generation Fire tablets, and Fire phone. The Amazon Maps API v1 is compatible with the Fire phone and all Fire tablets except Kindle Fire (1st Generation)."

https://developer.amazon.com/docs/maps/faq.html

Did not know about this, thanks for sharing. It almost increases the mystery in my mind. It appears this API is only available for use in Amazon Android apps, it's certainly marketed that way. It's as if they went 99% of the way of having a full map offering, but decided that Maps were somehow going to drive Kindle Fire adoption. Very interesting.

More likely than not, because the data is not theirs (I think it's Navteq->Nokia->Here), they wouldn't be able to resell it with a markup at a competitive price, so they don't even try.