While mobile technologies are moving closer to our body and novel wearable gadgets and smart textile interfaces emerge, current approaches are often expensive individual solutions for specific applications and lack reconfiguration possibilities. With this work, we introduce BodyHub, a modular wearable approach that allows users to realize their own smart garment applications by arranging and configuring exchangeable functional modules. To address individual user requirements and preferences, we developed a comprehensive repertoire of input and output modules that can be placed freely onto slide-in sockets which are imprinted in the textile by using 3D printing. Further, we developed a smartphone companion app that facilitates the creation of user-defined system functions without any programming skills. BodyHub thereby allows the creation of personalized wearable solutions by the users themselves and also supports ad-hoc assemblies for interface design explorations in research labs. To demonstrate the range of possible applications, we describe real-world use-cases from the areas of work life, shopping, mobility, and gaming.