Tools on the web can be used on computers, phones and other internet devices.
Forio, from Forio Online Simulations, allows you to build web based interfaces to models you have developed and also provides a library of interactive environments for curious users to explore. The software is web hosted, with a commercial use license, but provides a number of options for low cost and no cost publication and proliferation of models and model results.
iMODELER, from iMODELER, allows you to build web based models. The software is free for educational purposes. It runs on all operating systems including smartphones and tablets.
Insight Maker, from Insight Maker, from Gene Bellinger.
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.
Stella Online from isee systems
BROADVIEW, BROADVIEW, Unravel, play, discover, decide and undertake. BROADVIEW helps to quickly get a complete overview of a complex situation.
CLD Tool from OST, the Eastern Switzerland University of Applied Sciences, is an open source web app to create CLD diagrams effortlessly. It is tablet, pencil, touchscreen, and even smartphone ready and supports any effort to think in systems. Suitable for moderation, discussions, lectures, and the classroom.