Hidden Grid is a visually stimulating app that facilitates cause and effect understanding as well as basic touch screen skills such as touch and drag. This simple app is designed to allow multi-touch (cause and effect) and also single touch (pointing). When the screen is touched, the black background lights up with a variety of colors, shapes and musical sounds. Lifting a finger causes the shapes and sounds to disappear. There are no controls to eliminate the auditory feedback. The black background and bright colors are highly effective for users with low vision. The extremely sensitive screen helps reinforce cause and effect with only the slightest touch, which is wonderful for users who have difficulty with arm and hand function. The single touch component assists in practicing finger isolation skills and the bright graphics are motivating for children who are visual learners. We trialed this app with a 30-month-old child who was recently diagnosed with severe autism. One of the therapy goals was to facilitate attention to task as well as understanding of cause and effect. The child quickly grasped the concept that he must touch the screen to cause the sights and sounds. He independently played with this app for 15 minutes without the need of any physical assistance. We find this simple app to be an effective tool for facilitating cause and effect as well as developing fine motor skills for tablet use. The app graphics are great for children who are visual seekers and the immediate feedback encourages continued practice of fine motor skills.