Falstad’s browser-based simulations have been a staple for me in the classroom for well over a decade, although one could easily argue that they are specifically designed for education. https://www.falstad.com/circuit/
The Circuit Simulator is particularly impressive. It’s an interactive, modifiable, animated circuit simulator app that runs in real-time (and is modifiable in real-time). The example below shows a High Pass Filter (RC), where the frequency is varied over time to show the impact on the output voltage.
