(Really) Basic Unity3D plugin for Google Play In-app billing Version 3 API.

Just import the file googleinapp.unitypackage in your Unity project.

You need to add the BILLING permission

<uses-permission android:name="com.android.vending.BILLING" />

as specified on the Android documentation.

The Unity package provides an example script on how to use this plugin.

1. Make sure that Android SDK is correctly installed and that the Google Play Billing Library package is downloaded.
2. Copy IInAppBillingService.aidl from <ANDROID_SDK_DIR>/extras/google/play_billing to <PLUGIN_DIR>/java/src/com/android/vending/billing.
3. Copy classes.jar from <UNITY_DIR>/Editor/Data/PlaybackEngines/androidplayer/bin to <PLUGIN_DIR>/java/libs.

The project should be able to build without errors on Eclipse.

After succesfully building the Android plugin you can copy the library jar file from the bin folder to your Unity project at Assets/Plugins/Android.