Open In-App Billing – is an open source library which provides an easy way for the developers to develop their apps/games in a way that one APK will work in all the stores and automatically use the right in-app purchase API under each store.
Open In-App Billing for Google Play, SlideMe, Amazon Store, Nokia Store, Samsung Apps, Yandex.Store, Appland, Aptoide, AppMall and Fortumo.
ProGuard rules for Open In-App Billing
Add the following lines to your ProGuard configuration proguard.cfg file in project.
# Open In-App Billing
# GOOGLE
-keep class com.android.vending.billing.**
# AMAZON
-dontwarn com.amazon.**
-keep class com.amazon.** {*;}
-keepattributes *Annotation*
-dontoptimize
# SAMSUNG
-keep class com.sec.android.iap.**
# NOKIA
-keep class com.nokia.payment.iap.aidl.**
#FORTUMO
-keep class mp.** { *; }
For more information about library please see Open In-App Billing website.