PulseModem A is an APRS client developed by Pulsely Consulting Limited. This iPhone application allows licensed Amateur Radio operators to read and report APRS location and messages. APRS, which stands for Automatic Packet Reporting System, is a digital communications protocol that enables the exchange of information among a large number of stations, both locally and globally.

With PulseModem A, Amateur Radio operators can send and receive APRS location and messages in two ways. Firstly, they can directly connect to the APRS-IS Network, which provides access to a wide range of APRS stations worldwide. Secondly, they can send APRS messages via amateur radios that support the VHF Band at 144MHz. This feature allows for off-the-grid operations, making it suitable for use in areas with limited or no internet connectivity.

One of the notable features of PulseModem A is its full AX.25 software AFSK modem, which enhances its capabilities for off-the-grid operations. This modem enables the transmission and reception of APRS data without relying on an internet connection.

Please note that APRS is a registered trademark of Bob Bruninga, who is credited with the development of the APRS protocol.