Heterogeneity has been an indispensable aspect of distributed computing throughout the history of these systems. In particular, with the increasing prevalence of accelerator technologies (e.g., GPUs and TPUs) and the emergence of domain-specific computing via ASICs and FPGA, the matter of heterogeneity and harnessing it has become a more critical challenge than ever before. Harnessing system heterogeneity has been a longstanding challenge in distributed systems and has been investigated extensively in the past. Making use of real infrastructure (such as those offered by the public cloud providers) for benchmarking the performance of heterogeneous machines, for different applications, with respect to different objectives, and under various workload intensities is cost- and time-prohibitive. To mitigate this burden, we develop an open-source simulation tool, called E2C, that can help researchers and practitioners study any type of heterogeneous computing system and measure its performance under various system configurations. E2C has an intuitive graphical user interface (GUI) that enables its users to easily examine system-level solutions (scheduling, load balancing, scalability, etc.) in a controlled environment within a short time and at no cost. In particular, E2C offers the following features: (i) simulating a heterogeneous computing system; (ii) implementing a newly developed scheduling method and plugging it into the system, (iii) measuring energy consumption and other output-related metrics; and (iv) powerful visual aspects to ease the learning curve for students. Potential users of E2C can be undergraduate and graduate students in computer science/engineering, researchers, and practitioners.