Screensaver helps eliminate image persistence in LCD displays.
LCD Scrub... Liquid crystal displays are susceptible to image persistence (what we used to call "burn-in" on old CRT monitors). Unlike CRTs, however, LCDs with image persistence can often be repaired with special video patterns, saving the cost of a repair or new display.
LCD Scrub uses recommended techniques from Apple, NEC, and other manufacturers (plus some of our own tricks) to gradually "scrub" away residual images from liquid crystal displays.