Company Falstad.com created these great apps:
Ripple Tank, Ripple Tank Lite, Mega Photo: Real-Time Effects, Mega Photo Pro, Mega Photo Glasses: Real-Time Camera Effects, Ripple Tank, Electrostatics, Fourier, DigitalFilters, Images 2048, Slidezilla - make videos with awesome transitions and filters (was Mega Slideshow), Menta-List Reborn, Mental Killer Reborn, and others..