PlantVillage Nuru is a publically supported, and publically developed application that uses a digital assistant to help farmers diagnose crop disease in the field, without an internet connection. Developed at Penn State University and in close collaboration with domain experts at the CGIAR centers the app uses Google’s Tensorflow machine learning tool and a database of images collected by crop disease experts across the world. The app is based on extensive research comparing the accuracy of machine learning models to human experts and extension work. This is continual research and the app will be constantly updated. The app also allows for a blended model where images are examined by AI and human intelligence through a cloud system. This app was developed with the International Institute of Tropical Agriculture, The International Potato Institute, CIMMYT and the United Nations Food and Agricultural Organization. We welcome further collaboration with public institutions. This app is a public good and is not commercial or backed by venture capitalists. We do not have advertisements or collect farmer data to sell to third parties. You can donate if you like https://plantvillage.psu.edu/. In addition to the diagnostic tool the app contains the library of knowledge that is on PlantVillage, the largest open-access library of crop health knowledge in the world.