Pocket Sergeant is a reference app designed for UK police officers, police staff, detention officers, PCSOs, law students, solicitors, and anyone interested in the UK criminal justice system. The app is recommended to new police officers by their training departments and has become the biggest user-led policing app. Pocket Sergeant offers a range of features to its users, including the ability to search criminal law definitions and points to prove in England & Wales, search crimes by keywords, print/share crimes, and access police regulations. The app also includes a contacts section containing police force and partner agency telephone numbers, CCCJS codes, and a reference library to view PDFs offline such as the PACE Codes of Practice. Pocket Sergeant has a night mode option, case file help, and witness statement checklists to ensure all key points are met. Users can keep their work life separate with the built-in calendar. Overall, Pocket Sergeant is a comprehensive app that is useful for anyone with an interest in the UK criminal justice system.