**ipone application prank android windup**

I am wanting to setup an application for Android or Iphone..The idea is to have a list of sentences along with single words that the user can push while in mid conversation with the victim, the conversation will need to be flowing with the victim so they think they are talking to a real person but it is a pre -recorded voice. This application will need to be setup so the user can call the victim and easily switch back to the soundboard on speaker phone and once they pick up start the conversation.. Basic graphics need to be implemented but need to be able to clearly get the soundboard with the voice above.