Spectroid is a real-time audio spectrum analyzer with reasonable frequency resolution across the the entire frequency spectrum.
Spectroid uses multiple FFTs overlapped in frequency in order to provide better frequency resolution at lower frequencies than a single FFT. The caveat of this method is varied impulse response and minor discontinuities in the frequency graph. The upside is that it can efficiently produce a frequency graph that better matches the frequency resolution of human audio perception. Even so, it is limited by the Fourier uncertainty principle, while human audio perception is not.