Simple Android Application

Name (TBC) An android application, which automatically sends blocked numbers to a voicemail where the user can leave a message. The application only lets through registered numbers that are on the phone. The application must have the following features 1. Call goes directly to voicemail once it is clear that the number is from a blocked call and the number is not registered on the users phone. 3. Once a voicemail has been left the phone hang ups 4. User is sent a regular voicemail message saying they had a missed call...just like a normal voicemail