Bests & Worsts Reviews from Amazon

I'm very disappointed with this app and amazon. I bought this app after my daughter showed she enjoyed the free version. However I just recently purchased a new kindle and as I downloaded the app to the new kindle it would not allow me to restore it to the full version. I can't believe I have to buy it again. I was under the impression that the app would be available to all kindles through the same account. Truly disappointing.