The Checkerboard Reversal Task (CRT) is a widely utilized experiment aimed at investigating visual processing and eliciting visual evoked potentials (VEPs). The experiment involves presenting a checkerboard pattern that alternates between two colors, such as black/white, red/green, or yellow/blue. The pattern is rapidly reversed, and the participant is asked to concentrate on the pattern while disregarding any extraneous stimuli. CRT is an effective method for exploring various visual processing functions, including attention, perception, and cognitive flexibility. This app provides real-time displays of the averaged response, enabling researchers to observe the elicited VEPs and draw inferences regarding the participant's visual processing abilities. However, this app is intended for demosntrations and neuroscience courses, and does not implement strict time synchronization.