Super-resolution optical fluctuation imaging (SOFI) is a super-resolution technique that achieves spatial resolutions below the diffraction limit by post-processing analysis with correlation equations, similar to FCS. While original reports of SOFI used fluctuations from stationary, blinking of fluorophores, FCS has been combined with SOFI where fluctuations are produced from diffusing probes to produce super-resolution spatial maps of diffusion coefficients. This has been applied to understand diffusion and spatial properties of porous and confined materials. This includes agarose and temperature-responsive PNIPAM hydrogels, liquid crystals,  and phase-separated polymers and RNA/protein condensates.