Pedagogical tools are designed to convey important lessons and allow people to improve their understanding of a problem or undertaking. Though in a sense, these are the goals of any successful system dynamics study, the pedagogical tools focus on the teaching part, not the analysis of novel situations.
SHEETLESS from sheetless.io is an on-line, browser-based, system dynamics tool (all latest browsers except MS-Edge). No install required. It is easy to use, has extensive documentation, and has easy model sharing options. Is ideal for teaching. Sheetless is free for teaching purposes.
InsightMaker®, from Give Team, is a powerful, free System Dynamics modeling tool that runs completely in the browser. It enables you to build, run, and share System Dynamics models without downloading or installing a single program.
NetLogo®, from Northwestern University, is a multi-agent programmable modeling environment. It has the ability to build system dynamics models. It is used by tens of thousands of students, teachers, and researchers worldwide. It also powers HubNet participatory simulations.
Stella, from isee systems.
VisualAivika 5®, from Aivika Soft, is an easy-to-use diagram editor that allows creating nice-looking Casual Loop Diagrams (CLD) as well as Stock and Flow Maps (SFM). There is also a simulation component that supports its own high-level modeling language. There is the equation editor, where you can define integrals, arrays, random functions. Moreover, VisualAivika supports the Monte-Carlo simulation, which allows providing Sensitivity Analysis. There are means for plotting charts on the diagram to show the results of simulation in a form of Time Series, XY Chart, and Deviation Chart. The results can be exported.