Lewis structures are important for learning chemistry as they serve as an essential link between the structure of chemical compounds and their function. Unfortunately, the creation of valid Lewis structures remains an elusive goal for many students. In recent years, several web-based programs have been created that allow students to receive immediate feedback on the structures that they draw; however, the interface in most of these programs is not naturalistic, and there is a significant learning curve for students. This article describes the development, features, and pilot testing of OrganicPad, an innovative and user-friendly program that has been designed to allow students to draw Lewis structures by using the natural user interface of a Tablet PC. (Contains 3 notes and 6 figures.)