I released my second addon that is called ofxKeyboardBacklightBrightness(openFrameworks addon).
App download : http://www.mediafire.com/download/82kc7y3f2dl7ocf/example_fft.app.zip
Source code : https://github.com/5c0tt411en/ofxKeyboardBacklightBrightness
Here is the demo video of audio-reactive example.