Mobile device auto responders that dynamically send customized automated messages that depend on the identity of an incoming call, on the location of the mobile device, on the speed of the mobile device, on the acceleration of the mobile device, and/or on the time of day. The automated message can be customized to include the location, speed, heading and/or acceleration of the mobile device as well as an estimated time of arrival over a predetermined stored route to a predetermined location. The automated message may be audio, video, email, iMessage™, instant message, or SMS message.