Nowadays, embedded consumer devices execute complex network and multimedia applications that require high performance and low power consumption. Moreover, Network-on-chip (NoC) has been proposed as new paradigm for SoC interconnection. For implementing complex applications on NoC platforms, embedded systems require high abstraction level optimizations. To achieve such optimizations, a flexible NoC simulator is needed that provides the essential evaluation metrics. In this paper, we present a new tool based on the Nostrum NoC simulator. We show that it is possible with the evaluation metrics obtained by this simulator to perform optimizations in dynamic network and multimedia applications at the system level. Based on the system level transformations and the new tool we developed, we design applicationspecific NoC platforms.