This work developed an open accessed Mobile Digital Culture Heritage (M-DCH) platform called Demodulating and Encoding Heritage (DEH) that allows users to download M-DCH contents and upload M-DEH contents. For the M-DCH content concern, DEH interprets M-DEH from the viewpoint of point, line, area and story/site. Point of Interest (POI) is the basic unit of M-DCH and can contain text plus image/pictures, video or audio. A Line of Interest (LOI) is a sequence of POIs in which a visiting sequence of the composed POIs is enforced to have the temporal or spatial view and interpretation of the contained POIs. An Area of Interest (AOI) is a set of POIs in which the composed POIs are related, but the visiting of them can be random. A Story/Site of Interest (SOI) can contain many units, in which each unit can be a POI, a LOI or an AOI, to describe a complete story or a site of culture heritage. For the technical concern, DEH defines a new scenario of the grouping function. A group in DEH is composed of a group creator/leader and some members. In addition to the regular group functions i.e., sharing the content to group members, which belongs to the "read" action, defined in common social network, e.g., FB, Line, and WeChat, DEH's grouping function allows the group creator/leader to have the privilege of modifying contents created by group members, which belongs to the "write" action. This function is especially needed for content creation and sharing that is instructed/advised/guided in the teacher-student way. A set of metadata elements was defined for POI, LOI, AOI and SOI respectively such that the system can conveniently manipulate the M-DEH contents. The DEH platform was implemented by utilizing many tools for web and mobile APPs, e.g., Django for web API and Node.js for mobile API, based on the techniques of Location Based Service (LBS) and Geographical Information System (GIS).