Over on GitHub, developer Jens Engfors has released Cascade-SDR, a free and open source web-based receiver app designed specifically for RTL-SDR dongles. Cascade-SDR uses a Python backend that owns the dongle and handles all the DSP, paired with a browser frontend for the UI, waterfall, audio, and maps. The two communicate over a WebSocket, which means you can run the backend on a Raspberry Pi or mini PC and access it from any browser, phone, or tablet on your network.

Cascade-SDR has a live waterfall and spectrum scope view, with click-to-listen demodulation for WFM, NFM, AM, SSB, and CW, complete with RDS decoding, FM stereo, and a Morse decoder. CascadeSDR also includes a wideband Sweep mode, a channel Scanner, IQ recording and replay, and a built-in antenna helper that tells you how to set up the RTL-SDR.com dipole kit for your tuned frequency.

It also supports decoding of various digital modes, including ADS-B, AIS, APRS, ACARS, DAB+, NOAA APT weather satellite images, SSTV, POCSAG/FLEX pagers, and 315 to 915 MHz ISM band devices like weather stations and TPMS sensors. However, to decode most of these modes it is necessary to install various decoder software that it is dependent on such as dump1090, AIS-catcher, direwolf, welle-clide, multimon-ng, and rtl_433. 

Cascade-SDR runs on Windows, macOS, and Linux/Raspberry Pi. The readme includes instructions on installing the software on the various OS platforms.

AI-Disclaimer: This software has used Claude for development.