Complex event detection over data streams has become ubiquitous through the widespread use of sensors, wireless connectivity and the wide variety of end-user mobile devices. Typically, event detection is carried out by a central server executing continuous queries. In this demonstration, we focus on the case where users with mobile devices submit continuous queries (for event detection) to a data stream management server which disseminates the results to the users over a shared broadcast medium. In order to minimize the overall energy consumption of the mobile devices (clients), we have proposed operator placement algorithms that split the processing of each continuous query between the centralized server and the requesting mobile clients, thus trading off energy consumption for communication energy consumption for computation. Specifically, in this demonstration, we present an interactive graphical interface to the inner workings of our three proposed operator placement algorithms, whereby attendees are able to investigate various query plans and the decisions that the algorithms make, as well as visualize the results of these algorithms in terms of client power consumption and response time. Besides being able to step through an algorithm's execution as it considers various operator placement decisions, attendees are able to experiment with different scenarios by customizing the parameters of the query workloads (e.g., changing the selectivities and projectivities of the operators) or the client's profile (e.g., power consumed per unit of time of processing) and examine the impact.