KOKOPIN is a social platform enabling field research of biodiversity using an iPhone application. Our application's camera and meta-data tagging functions facilitate easy data collection. Customizable groups are another unique feature of this system. This paper introduces our initial design process, and some on-going field projects using KOKOPIN. KOKOPIN's development was motivated by the Dandelion Survey in West Japan, a participatory biodiversity research project. The system consists of an iPhone App and backend servers. The platform was designed to accept a variety of data types optimized by a project administrator. As examples of usage, biodiversity data from the Campus Flora Project and the Wooden Assets Management of the Kyushu University Museum were reported. The application was designed as a versatile platform, and recently it started to be accepted not only for biogeography research but also for non-biological services.