OpenIABKivy

http://www.onepf.org/openiabOpenIAB is a unified protocol for in-app purchases on Android and a library that supports in-app purchases from all big stores including Google Play, Amazon Appstore and Samsung Apps as well as multiple smaller stores such as Nokia, Yandex.Store, SlideME, Appland, Aptoide and AppMall.
http://www.kivy.orgKivy is fun, but its current implementation of in-app billing relies on in-app billing version 2 of Google, which will be discontinueted as of january 27th 2015.

this app is a proof of concept for the usage of Kivy alongside to openIABsource code is available here:

https://github.com/niavlys/openIAB4Kivy