Service of Incoming Calls

The application has service which monitors all incoming calls and two lists of contacts - black and white.
If a contact is in black list, its incoming call will be immediately interrupted.
If a contact is in white list, its incoming call will be received in normal way.
If contact of incoming call is unknown, the system notification offers to put it to black or to white list.
Both lists can be edited manually. Long touch on list item opens context menu for the contact. Pressing on up-right blue icon allows create new contact in the list.
The service is stopped at the first moment. It has to be switched on only one time. It will be work all time even the device rebooted until it will manually switched off.
SMS answering machine.