Receptor that plays a role in the regulation of synaptogenesis and dendritic spine formation at least partly via interaction with ELMO1 and RAC1 activity (By similarity). Promotes myoblast fusion through ELMO/DOCK1 (PubMed:24567399). . This is the function of ADGRB3 (adhesion G protein-coupled receptor B3, Ensembl gene identifier ENSG00000135298).