In a previous article, we conducted a Systematic Mapping Study (SMS) devoted to identifying the open-source IoT platform that nowadays offers the most features as well as adequate documentation and which, therefore, is a useful middleware in the development of IoT applications. In light of the final findings of such a study, ThingsBoard was selected. The present paper reports on the findings of a subsequent mapping study. We queried the Scopus database looking for articles that mention ThingsBoard either in the Title, in the Abstract, or among the authors' Keywords. 55 items were retrieved and carefully read. At the end of this stage, we were able to answer the following research questions: Are there available studies mentioning ThingsBoard? In which ambits? What is the role of ThingsBoard in the studies where it is mentioned? What are the gaps in current research and the implications for future research? The study goals are general, so the final findings might be of interest to IoT professionals, as well as to scholars. In detail, the SMS provides insights into the breadth of usage and the domains where ThingsBoard has been applied successfully, indicating its suitability and potential for a wide range of IoT-related projects. Moreover, a few gaps to be filled with further research have emerged.