After SmartRace has been available on Amazon since August 2016, I decided to cease the native support for Amazons Fire devices. It turned out that the effort that it takes to maintain and update the app for another platform is much higher than the gains. I never expected the demand to be high, but in the end it was even lower than my most cautious predictions. Another downside is the lacking support of in-app purchases for cordova-based applications. I was just not willing to implement a special solution for IAP for the Amazon platform. Though it is not per se an issue to not have the IAP available on Amazon, it turned out that SmartRace users had the (understandable) expectation they would be able to purchase them also on Fire devices (which was not possible).
In the end it was not an easy decision, but a logical one for me as I need to focus my efforts and limited available time on the main platforms iOS and Android. I hope you will understand why I had to take this decision. If you need help with the transition from Amazon to iOS or Android, please let me know.