English: Machine learning models designed to improve citation quality in Wikipedia, such as text-based classifiers detecting sentences needing citations (“Citation Need” models), have received a lot of attention from both the scientific and the Wikimedia communities.However, due to their highly technical nature, the accessibility of such models is limited, and their usage generally restricted to machine learning researchers and practitioners. To fill this gap,we present Citation Detective, a system designed to periodically run Citation Need models on a large number of articles in English Wikipedia, and release public, usable, monthly data dumps exposing sentences classified as missing citations. By making Citation Need models usable to the broader public,Citation Detective opens up new opportunities for research and applications. We provide an example of a research direction enabled by Citation Detective, by conducting a large-scale analysis of citation quality in Wikipedia,showing that article citation quality is positively correlated with article quality, and that articles in Medicine and Biology are the most well sourced in English Wikipedia.