TimePrompt triggers green, yellow and red lights in pre-programmed sequences from 15 seconds to 90 minutes. The timer can count up or count down, and beep manually or automatically on the light changes. Light sequences that are preset can be reprogrammed via a free programmer application that runs on a USB-connected PC.  As soon as the clock starts, the TimePrompt digital display changes to show the time remaining or the elapsed time depending on the mode.  For sophisticated applications, two TimePrompts can be connected by ordinary data cable. One can act as a remote signal light; the other acts as a controller.