This is a port of Android NDK sample (sanangeles). http://developer.android.com/tools/sdk/ndk/index.html#Samples
The project contains pre-compiled libsanangeles.so under libs directory (armeabi, armeabi-v7a and x86 are supported).
This library sample is easily ported because there is no dependency on any jobject instances or JNIEnv instance in C code.