Signals sensed from packaging of products are processed in a distributed reader and metadata routing system to provide metadata responses to mobile application programs. A routing system registers identifiers for different content ID schema. These identifiers are encoded packaging. Mobile device application programs are equipped with reader programs to extract identifiers from packaging. Metadata responses are identified by the ID provider of the content ID schema and extracted identifiers. The metadata routing system routes metadata responses to a requesting mobile device, supporting a variety of different ID providers and mobile device applications.