Lewis structures are a very important, foundational concept in chemistry. Students usually acquire this knowledge in General Chemistry and need to review it in preparation for Organic Chemistry. However, many students find the task of drawing Lewis structures to be challenging, and not all instructors can budget enough time in class to review this material when they start Organic Chemistry. To address this issue, we created a web application (web app; Lewis Structure Builder) that lets students review Lewis structures in their own time, allowing them to position individual atoms, build and break bonds, and get real-time feedback on the accuracy of their structures. The web app was designed to be intuitive, requiring very little training to use, and students could use desktops, laptops, or mobile devices to participate. In working through a sequence of target molecules to build, students had the freedom to try out different atomic structures to see what works and receive real-time feedback about their decisions. Upon successful completion of a molecule, students received visual and haptic feedback as a form of positive reinforcement. Afterward, students saw their solution next to the same molecule shown as an extended structure and as built using a model kit. A pilot study was conducted with 37 students who were enrolled in Organic Chemistry I. Participants were given an assessment to determine their level of proficiency in drawing Lewis structures, followed by an opportunity to use the web app and a post-test. After using the web app, 21% of the participants showed improved outcomes, and most students reported satisfaction with the user interface and perceived benefits from the experience.