Unity2AndroidMessage
Sample string message sending from unity to android.
Method that handles unity3d ui action creates AndroidJavaClass object that allows to work on MessageDispatcher java class. It calls static method BroadcastMessage with string param. On Android side MessageDispatcher when recives new message sends local broadcast with message. By default it's recived by UnityPlayerActivity which shows Toast with received message.
Android project can be found under Unity2AndroidMessage/AndroidProject/Unity2AndroidMessage