Android service controlled by power/volume button

I need a android application that includes a background service that invoke shell commands when the power or volume button is pressed 3 times in a row in 2 seconds. A sound(beep or any notification) should be played when the shell command is invoked. The background service should always run, starting at boot and should work even if the screen is turned off and the device is in sleep. The shell command. for testing. should be "touch /sdcard/[login to view URL]" A log line (logcat) should be displayed on each button press. The Main Activity should contain nothing than a text message. Full source code is required. I consider this project to be very simple challenge with no long-term value, please consider that while bidding.