Technologies collecting location-based data in the real world have advantages over traditional methods for landscape perception research. The possibility to relate geo-referenced responses of inhabitants to the physical and social data in expert GIS databases can lead to new insights into the difference between laymen and expert opinions and may result in adjustments of policy forming. To date, the use of Social Sensing in Landscape perception and valuing is limited. This research presents the set of requirements for a mobile application for landscape and urban planning, discusses some of the main challenges, and concludes that a number of evaluated existing mobile applications just partly meet those requirements.@en