Social sensing via mobile apps complements physical sensing (e.g., IoT) by substantially extending the horizon we know about our daily life in real time. This paper discusses how we can integrate physical and social sensing to enable better and smarter services, focusing on enriching riders' experience of using bike sharing services in New York City. We show how we real time collect, process, and model data on riders' profiles and mobility needs, and from citibike and social media. With the support of big data technologies, we conduct data integration and aggregation to develop a smart service system by focusing on meeting the needs of riders in real time. The developed prototype in support of city mobility management and operations reveals the great potential of providing riders enriched user experience.