Soft Phone Soft phone is software program for making telephone calls over the Internet using a computer, handheld device or a mobile phone. Features and buttons such as the dialing pad, DND option and caller ID will be on the screen, just like an actual phone. These software can be installed on certain mobile phones, creating a platform for making calls, without using your airtime minutes. How it works: Install the softphone software program on the computer. Set up the softphone with the given settings information, and once activate, you may dial to your desired number.