Tinkercad is a super easy-to-use, browser based 3D design tool. With Tinkercad you can create 3D printable items: toys to play with, decoration to light up your home or jewelry to express yourself. You dream it, you can make it!
A web-app you can use to simulate circuits as well as run Arduino sketches right in the browser, using the open-source AVR8js platform.
Wokwi Arduino Simulator vs UnoArduSim opinions
Wokwi works on the browser, which is a major advantage compared to the Windows-only UnoArduSim. Wokwi's user interface is also more polished and modern.
However, UnoArduSim does have code debugging with support for step-into, -over and -out, and viewing the call stack.