The home page of the app provides large, colorful links to the individual tours, as well as icons for setting font size and online status (far left), searching by architect, location, or content (magnifying glass icon), reading architectural news from the Prairie Design blog (the "newspaper" icon), or an overall map showing all tour locations.
The app's navigation tools are sparse and don't get in the way. From left to right, they include a way to get to the home page, show or hide audio controls, provide detailed address and location information, and a map.
The maps in the app can be either Google maps (online) as in this photo or offline maps. Tapping the location icon at the lower right provides a blue "pin" at your current location, making it easy to find your way between the tour sites. To see a picture of the next building on the tour, you click the large yellow right-pointing arrow.