The Horizon 2020 project CrossCult aims to highlight historical and cultural associations between different characters, locations, events, venues, or artworks, to develop new strategies with which to promote intercultural and cross-border aspects of history and heritage. This paper presents a pilot app that provides graph-based visualizations of those associations, arranged by Humanities experts in relation to several reflective topics, and glued together by narratives that may present the same facts from diverse points of view. After querying a knowledge base that brings together several Linked Data resources, the associations are curated by the experts using a dedicated tool, to ensure that only meaningful associations appear on the mobile app. In turn, the app users can contribute new associations in the form of written text, which the experts can turn into new concepts and properties in the knowledge base. Here, we present the design of the mobile app and the experts' tool, together with the results of early experiments aimed at assessing the instructional value of the proposal.