SilentPhone, formerly BlackPhone, does a decent job: https://www.silentcircle.com/products-and-solutions/silent-phone/ https://www.silentcircle.com/products-and

SilentPhone, formerly BlackPhone, does a decent job: https://www.silentcircle.com/products-and-solutions/silent-phone/ https://www.silentcircle.com/products-and-solutions/silent-p...