Map application is usable directly in the field thanks to its geolocation using GPS. It briefly and clearly describes geologically interesting sites in the Czech Republic - natural geological outcrops, caves and karst phenomenon or remains of human activities, mainly of mining origin. Description of the geosite includes a photo, note of its protection and other references. Moreover one can choose layer Decorative stones with basic information about displayed objects. Base maps - detailed topographic maps and aerial photos - are provided by the company Seznam.cz, a.s. The application is based on CGS own technology to display map services using ESRI API 3.x. Its functionality and design are optimized for touch devices and small displays.