WaveSpectra is described as 'tool that (FFT fast Fourier transform) an audio signal as input and sound card, the Wave file, and displays the frequency components (spectrum) in real time'. There are nine alternatives to WaveSpectra for a variety of platforms, including Windows, Linux, Mac, Android and VSTHost. The best alternative is Friture, which is both free and Open Source. Other great apps like WaveSpectra are Spectroid (Free), Signalizer (Free, Open Source), Spectralissime (Free Personal) and Visual Analyser (Free).
Real-time audio spectrum analyzer with reasonable frequency resolution across the the entire frequency spectrum. - Spectrum - Waterfall - Max-hold trace - Peak markers - Linear or logarithmic frequency scale
Signalizer is a all-in-one signal visualizing package with a bunch of unique focus-points; real-time audio visualization with optimized 3D GPU graphics, everything being scalable and zoomable gridlessly as well as being arbitrarily precise in both settings and display.
iSpectrum is an easy to use audio spectrum analyzer that allows you to view live audio in a standard frequency plot, a stereo oscilloscope view and a waterfall display. You can adjust the display resolution, center frequency and save images to disk.
TrueRTA's audio spectrum analyzer software shows you a detailed picture of what you're hearing in real-time, that is, as it happens. You can create your own professional measurement system starting with TrueRTA software on your PC.