Advancements in sensor network have evolved rapidly in recent years, and devices are smart enough to build and manage their network and route optimization referred to as Internet of Things (IoT). Numerous IoT operating systems (OSs) are developed for resource-constrained IoT devices. Contiki IoT OS is a widely used IoT OS by researchers and practitioners. Contiki-OS Cooja emulator is recognized as one of the favourite tools of researchers for running large-scale simulations and observing the results before the real-time deployment. Cooja generates execution logs for all the activities of the network simulation. However, there are no tools or programs available to summarize and analyse the big log files generated by Cooja. This slows down the research pace for complex network scenarios and makes it difficult to compare with existing bench marks and research work. In order to help researchers, an evaluation tool which gathers information, analyses and develops simulation log results is required. It provides detailed individual mote statistics as well as complete IoT network statistics. In this chapter, we discuss three algorithms and their merits and demerits. First, the proposed scheme scans the generated log file and provides summary of all the IoT motes in separate files. This technique is useful for very large files and complex operation, although it requires more hard disc space for temporary files. Second, the proposed algorithm scans log file to summarize data in memory. This algorithm requires additional space for temporary files and scans source files many times consequently, and it requires more time to complete the evaluation. Third algorithm scans log file exactly once, does not require any additional space for temporary files and computes summaries in memory. It makes processing really fast, and can work without temporary files generated. All three algorithms are helpful in different IoT deployment scenarios; therefore, researcher can choose according to their preference of memory requirements, file sizes, and time constraints.