A system comprising: a server configured to: establish a voice communication link with a client device, once a telephone call to a telephone number associated with the server is received by the server from the client device; send a launch command associated with a designated application to the client device via the voice communication link, wherein the launch command comprises a set of audio signals or a set of dual-tone multi-frequency signals that is transmitted over the voice communication link, wherein the launch command received from the server is configured to cause the designated application to be launched at the client device; and the client device configured to: call the telephone number associated with the server; translate the launch command received from the server into a set of values based on using stored data that indicates correspondences between a plurality of launch command signals and a plurality of values; use the set of values to launch the designated application, without user intervention, based on comparing the set of values to stored data to determine that the set of values corresponds to a stored preset set of values corresponding to the designated application; and exchange information with the server over the voice communication link using the designated application, wherein the designated application is configured to receive user input information into a user interface of the launched designated application. a server configured to: establish a voice communication link with a client device, once a telephone call to a telephone number associated with the server is received by the server from the client device; send a launch command associated with a designated application to the client device via the voice communication link, wherein the launch command comprises a set of audio signals or a set of dual-tone multi-frequency signals that is transmitted over the voice communication link, wherein the launch command received from the server is configured to cause the designated application to be launched at the client device; and the client device configured to: call the telephone number associated with the server; translate the launch command received from the server into a set of values based on using stored data that indicates correspondences between a plurality of launch command signals and a plurality of values; use the set of values to launch the designated application, without user intervention, based on comparing the set of values to stored data to determine that the set of values corresponds to a stored preset set of values corresponding to the designated application; and exchange information with the server over the voice communication link using the designated application, wherein the designated application is configured to receive user input information into a user interface of the launched designated application. establish a voice communication link with a client device, once a telephone call to a telephone number associated with the server is received by the server from the client device; send a launch command associated with a designated application to the client device via the voice communication link, wherein the launch command comprises a set of audio signals or a set of dual-tone multi-frequency signals that is transmitted over the voice communication link, wherein the launch command received from the server is configured to cause the designated application to be launched at the client device; and the client device configured to: call the telephone number associated with the server; translate the launch command received from the server into a set of values based on using stored data that indicates correspondences between a plurality of launch command signals and a plurality of values; use the set of values to launch the designated application, without user intervention, based on comparing the set of values to stored data to determine that the set of values corresponds to a stored preset set of values corresponding to the designated application; and exchange information with the server over the voice communication link using the designated application, wherein the designated application is configured to receive user input information into a user interface of the launched designated application. call the telephone number associated with the server; translate the launch command received from the server into a set of values based on using stored data that indicates correspondences between a plurality of launch command signals and a plurality of values; use the set of values to launch the designated application, without user intervention, based on comparing the set of values to stored data to determine that the set of values corresponds to a stored preset set of values corresponding to the designated application; and exchange information with the server over the voice communication link using the designated application, wherein the designated application is configured to receive user input information into a user interface of the launched designated application.