ISPs around the world are currently exploring new pricing strategies, such as usage-based pricing in the U.S., on their wired and wireless networks. A next step in this evolution of pricing practices is Time Dependent Pricing (TDP) [1], [2], which creates a win-win opportunity for ISPs and consumers: ISPs can reduce cost and monetize bandwidth, while consumers save money by choosing the time of usage. TDP uses a feedback control loop between an ISP and its users to account for users’ responses to offered prices in optimizing the future prices. Implementing a functional and complete system for TDP of mobile data requires several architecture and design choices, for both the ISP-side architecture and the user interfaces (UIs). We have completed the first-of-its-kind implementation of such a system, and are conducting a user trial at Princeton. Our implementation is currently being tested by our partner ISPs [3]. This demo will introduce the audience to our system’s serverand client-side features. In particular, the audience will view network congestion conditions and respond to the offered TDP prices by using our client-side UIs for Android, iOS, and Windows devices.