Happy New Year!! Version 6.1.1 is out just in time for the spring quarter/semester. This includes improvements in the world view and model parameters that you can sync across multiple models in the Model Builder.
To upgrade, click the green "Now available" button on the toolbar and choose Upgrade Now. If you don't see the green button choose Help|Check For Upgrades.
You can also download installers directly from the Tracker home page (http://physlets.org/tracker/) or ComPADRE (http://www.opensourcephysics.org/items/detail.cfm?ID=7365).
I hope 2023 brings you many curious students and much success in your classrooms! Doug