Fritzing use vs sim like Falstag

As @gtmize mentioned, there is a basic simulator in Fritzing (but will not simulate Arduinos). Check the current capabilities here: https://blog.fritzing.org/2022/06/27/Simulating-Circuits-with-Fritzing

In addition, you can also simulate transitory analysis since Fritzing 1.04. It is still a beta feature but it is functional. To use it, you must launch Fritzing in debug mode (using the terminal and adding the argument “-d”) and select the transitory mode in the simulation button. Please, notice, that there are not many parts that have spice models. See an example using a 555 and more info about the transitory analysis in this thread: Using 555 timer chip doesn't work