Cell Electrophysiology Simulation Environment is a framework to perform electrophysiological simulations. It can, for example, simulate cardiac myocyte electrical activity. It is useful for simulations of action potentials, individual ionic currents, and changes in ionic concentrations.
ChangeBlindness is a small game that demonstrates the change blindness phenomenon. The effect shows that our brains have a low-level (i.e. subconscious) change detection capability that can be disabled pretty easily (for instance, with a flicker of around 100ms). The game illustrates this using an increasing number of icons, one of which will change during a flicker. The goal of the game is to find the changing icon as quickly as possible.
ImageJ is an image processing program inspired by NIH Image for the Macintosh. It can display, edit, analyze, process, save, and print 8-bit, 16-bit, and 32-bit images. There are modules for biology, astronomy, nuclear medicine, physics, and more. If you can take a picture of something, whether with a microscope, a telescope, an oscilloscope, an xray machine, or a scanner, then this program will let you enhance, manipulate, and measure the results.