rtl_tcp SDR is an RTL-SDR Software Defined Radio receiver app designed specifically for iOS devices. With this app, users can listen to various radio signals, including AM, FM, SSB, and CW. The app also provides a visual representation of the RF spectrum and waterfall.

To use rtl_tcp SDR, an external rtl_tcp server is required. Since iOS devices do not support direct USB connections, the app relies on network access to a server, such as a Raspberry Pi or Mac, with an RTL-SDR unit connected via USB. The rtl_tcp protocol is used to establish a TCP/IP connection between the server and the iOS device, allowing the server to act as a USB port adapter.

In addition to rtl_tcp, the app can also connect to other tcp servers such as hfp_tcp for the Airspy HF+, rsp_tcp for SDRPlay devices, and lmm_tcp for the LimeSDR Mini. No support is provided for installing these servers, so users should only download the app if they are already familiar with Software Defined Radio and have the necessary hardware and software setup.

Please note that rtl_tcp SDR requires a high bandwidth network connection to receive real-time RF samples from an RTL-SDR. It is recommended to have the rtl_tcp server on a wired connection for optimal performance.