The Civil War in St. Louis app, produced for both Apple and Android devices, highlights historical sites based on the William Winter book of the same name. The app features an interactive map outlining recommended tour routes, archival and contemporary photographs, original audio tours, and interpretative text. The app is part of the Missouri History Museum's commemoration of the sesquicentennial of the U.S. Civil War, the Civil War in Missouri exhibition.

Central to the app's function, the self-guided map routes users through a recommended tour of key Civil War sites in St. Louis. The Google-based map includes nearly 50 points of interest (POIs) at key sites, marked by custom icons. When users touch each point, the name of the location appears. A second touch activates screens detailing information about the tour stop. Following the route, users can experience these historic locations—those still in existence and those that have been built over or torn down during the past 150 years.

Each POI on the map has an historical overview, a multimedia gallery of captioned images, and general location information. Each of the primary tour stops features an audio tour. Hundreds of images—archival and contemporary—help users visualize what it would have looked like and what it looks like today. Images enlarge with a touch and can be zoomed in to view closer details.

The sites are indexed, so if a user wants to quickly access information about a specific site, they can scroll through to jump there directly.

The app is designed to run off a master XML file so that if future edits are needed to the text or captions, editors at the Missouri History Museum can facilitate those updates themselves. The total app file size was kept deliberately small—around 10 MB total—so users could download it without a WiFi connection.