The Illinois Open Space application is a software application that helps people find and manage open space areas in Illinois. This application allows users to search for open space areas by zip code, city, or county. It also provides detailed information about the open space areas, such as acreage, access points, and amenities. The Illinois Open Space application also allows users to create and save their own custom maps. There are two types of Illinois Open Space applications available: the free version and the paid version. The free version provides basic search and mapping features, while the paid version offers additional features, such as custom layers and advanced analysis tools.