ArcGIS is a great way to discover and use maps. Maps come to life in ArcGIS. Tap on the map or use your current location and discover information about what you see. You can query the map, search and find interesting information, measure distances and areas of interest and share maps with others.
GeoMobile for ArcGIS is a free ArcGIS mobile viewer.
It is highly customizable, and allows analysis and visualization of spatial data in ArcGIS. The application lets users load their own map layers via a Web hosted configuration file. It also includes a range of tools including annotation/measure, interactive overview map, geo-coder, search, routing and a geolocator.