Android NDK simple
===

I'm a newbie with the Android NDK and so I hope my question is not a stupid one. 

I followed this tutorial, found on this link:

http://mindtherobot.com/blog/452/android-beginners-ndk-setup-step-by-step/

Everything worked smoothly, I followed every instruction. However, when I ran the application, it's giving me these errors in my logcat:

    07-20 07:35:25.253: D/dalvikvm(390): Trying to load lib /data/data/com.example.testndk/lib/libndkfoo.so 0x40515310
    07-20 07:35:25.253: D/dalvikvm(390): Added shared lib /data/data/com.example.testndk/lib/libndkfoo.so 0x40515310
    07-20 07:35:25.253: D/dalvikvm(390): No JNI_OnLoad found in /data/data/com.example.testndk/lib/libndkfoo.so 0x40515310, skipping init
    07-20 07:35:25.503: W/dalvikvm(390): No implementation found for native Lcom/example/testndk/NdkFooActivity;.invokeNativeFunction ()Ljava/lang/String;
    07-20 07:35:25.513: D/AndroidRuntime(390): Shutting down VM
    07-20 07:35:25.513: W/dalvikvm(390): threadid=1: thread exiting with uncaught exception (group=0x40015560)
    07-20 07:35:25.534: E/AndroidRuntime(390): FATAL EXCEPTION: main
    07-20 07:35:25.534: E/AndroidRuntime(390): java.lang.UnsatisfiedLinkError: invokeNativeFunction
    07-20 07:35:25.534: E/AndroidRuntime(390): 	at com.example.testndk.NdkFooActivity.invokeNativeFunction(Native Method)
    07-20 07:35:25.534: E/AndroidRuntime(390): 	at com.example.testndk.NdkFooActivity.onCreate(NdkFooActivity.java:23)
    07-20 07:35:25.534: E/AndroidRuntime(390): 	at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1047)
    07-20 07:35:25.534: E/AndroidRuntime(390): 	at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:1611)
    07-20 07:35:25.534: E/AndroidRuntime(390): 	at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:1663)
    07-20 07:35:25.534: E/AndroidRuntime(390): 	at android.app.ActivityThread.access$1500(ActivityThread.java:117)
    07-20 07:35:25.534: E/AndroidRuntime(390): 	at android.app.ActivityThread$H.handleMessage(ActivityThread.java:931)
    07-20 07:35:25.534: E/AndroidRuntime(390): 	at android.os.Handler.dispatchMessage(Handler.java:99)
    07-20 07:35:25.534: E/AndroidRuntime(390): 	at android.os.Looper.loop(Looper.java:123)
    07-20 07:35:25.534: E/AndroidRuntime(390): 	at android.app.ActivityThread.main(ActivityThread.java:3683)
    07-20 07:35:25.534: E/AndroidRuntime(390): 	at java.lang.reflect.Method.invokeNative(Native Method)
    07-20 07:35:25.534: E/AndroidRuntime(390): 	at java.lang.reflect.Method.invoke(Method.java:507)
    07-20 07:35:25.534: E/AndroidRuntime(390): 	at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:839)
    07-20 07:35:25.534: E/AndroidRuntime(390): 	at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:597)
    07-20 07:35:25.534: E/AndroidRuntime(390): 	at dalvik.system.NativeStart.main(Native Method)

Does anyone have a slight clue what the issue may be? I've tried to figure it out and even started the tutorial from scratch, however the problem persists. Thanks in advance.