In this paper, we present a corpus for heritage Bosnian/Croatian/Montenegrin/Serbian (BCMS) spoken in German-speaking Switzerland. The corpus consists of elicited conversations between 29 second-generation speakers originating from different regions of former Yugoslavia. In total, the corpus contains 30 turn-aligned transcripts with an average length of 6 min. It is enriched with extensive speakers’ metadata, annotations, and pre-calculated corpus counts. The corpus can be accessed through an interactive corpus platform that allows for browsing, querying, and filtering, but also for creating and sharing custom annotations. Principal user groups we address with this corpus are researchers of heritage BCMS, as well as students and teachers of BCMS living in diaspora. In addition to introducing the corpus platform and the workflows we adopted to create it, we also present a case study on BCMS spoken by a pair of siblings who participated in the map task, and discuss advantages and challenges of using this corpus platform for linguistic research.