As any electric piano player will tell you, a tremolo effect is a highly desirable tool to have in your arsenal, and Adam Monroe is now being kind enough to offer you one for free.
As well as offering the tremolo (or amplitude modulation) effect, this does stereo panning and gives you speed and depth controls for both processors. You can control the dry/wet mix, and changing the sample rate also increases or decreases the speed of the modulation.
You can download Tremolo now from the Adam Monroe website. It's available for PC and Mac in VST/AU formats.