Default Need help for developing Answering machine app

Hi,

I want to develop an Android app which for answering machine. The app will work as follows,
When the call comes, if the user is unable to receive the call the app will get on and will ask to leave a message. App will record the message and will save it with name, time and number and will play the recorded file when the user wants.

Is this possible? If it is then can some please guide me on this how I can develop it.

Many Thanks...