The article introduces the PlantVillage Nuru mobile app, which uses AI to identify plant diseases, with a focus on potato crops. This app is designed to assist the over two million potato growers in East Africa who rely on their crop's success. The app's development began as a tool to detect cassava diseases, outperforming human workers, and has now been extended to include potato diseases. The app's functionality involves users pointing their smartphone at the plant, receiving an immediate diagnosis based on thousands of images of healthy and diseased potato leaves that have been used to train the app's neural network.