.
With this application you can:

.answer calls with the Home button

.reject Calls with the Back key

You can use this App even if your device already has the built-in option to answer calls with the Home button; this App has the added ability to reject the call using the back key.

Advanced PRO Functions:

. no Wait Message when phone is ringing

. option to don't show Pop-up message

This app is clearly not compatible with all devices: I personally tested and works with Samsung Galaxy S, S2 and Notes II (stock Samsung).

Before purchasing the PRO version try the free to check if it is compatible with your device.