Kindle Musescore App is not up-to-date

First of all, in the Amazon App shop there is only the full version of Musescore available for download, unlike to the Android Google Play store , where you can download a free demo version with limited features as well. Why do these differences exist between these two shops?
Now to my main problem: About a half year ago I downloaded this free version on the Google Play store and installed the APK on my Kindle Fire tablet. I have used it many times and I find it very useful, so I wanted to buy the full Musescore app (you definetely deserve it, the app is so great!). Now, since the Musescore App that can be bought on the Amazon shop would be the same as the one on the Google Play store, I wanted to buy it on the Amazon App shop (If I would buy it on Google Play, I would have to root my Kindle, because the trick to install Android APKs on a Kindle without rooting only works with free Android Apps), however I compared the two versions on the different shops and saw that the Kindle App is not up to date anymore:

• The Android version is version 1.8
• The Kindle version is version 1.7.1

Furthermore, on the Google Play store it says:

New features
- Open MuseScore 2.0 files
- Cursor on score starting with multi measure rests

Which it doesn't on the Amazon App shop.
Therefore I have to assume that you are no longer updating the Kindle version, since it is rather unlikely and disadvantageous to use different version numbers for the same build (only for different OSs).
I hope you update the Kindle Fire app , because I want to be able to open Musescore 2.0 files, if I pay 5.99 € for this app. Come on, porting from Android to Kindle cannot be that hard: You can literally take the Android APK and install it directly on the Kindle in the most cases (including at least the free demo version of Musescore).
So I hope you fix that issue and keep publishing updates on the Amazon App Shop, which can be expected if one pays 5.99 € for the app.
The app is really great (as well as Musescore Desktop), so it would be a shame if you would lose the Musescore Fans having a Kindle Fire, although porting from Android to Kindle is not so much work. :)