Apple continues to work on stylus technologies for its iOS devices, as seen in a recent patent. The stylus uses an electrode at the tip to affect the stylus’ reaction to a touchscreen, similar to what Griffin did in its previously-released iMarker and Crayola ColorStudio HD. This wouldn’t be the first time Apple’s filed a patent for an active stylus of some sort. In May, an Apple patent application discussed a battery-powered stylus…