I'm trying to find an app that would undo or reveal a caller's true number when they call. I have received some harassing/threatening phone calls last night and the caller used (what I'm assuming) an application to disguise their voice and an app to mask their caller ID. After calling Sprint and the local police, it looks like I won't be able to really get anything started until 7-10 business days. If I had an app that would reveal their real cell phone #, I could turn this info over to the police and (I'm sure) expedite the process. Any help with this would be greatly appreciated. Thanks!