Universal Radio Hacker is described as 'urh - Universal Radio Hacker: investigate wireless protocols like a boss Features include: - hardware interfaces for common Software Defined Radios - easy demodulation of signals - assigning participants to keep overview of your data - customizable decodings to crack even'. There are three alternatives to Universal Radio Hacker for Linux, Mac, Windows and BSD. The best alternative is GNU Radio, which is both free and Open Source. Other great apps like Universal Radio Hacker are Baudline (Free) and inspectrum (Free, Open Source).
Baudline is a time-frequency browser designed for scientific visualization of the spectral domain. Signal analysis is performed by Fourier, correlation, and raster transforms that create colorful spectrograms with vibrant detail.