I came across Partsim, a free and easy to use circuit simulator that runs in the web browser, and would definitely encourage you to check it out if you’re looking for a tool to design and simulate circuits.

It supports a wide variety of components, and even supports Digi-Key integration to make it easy to buy your project once you’ve seen its results. That’s a great feature! Anything to take some of the pain out of generating a Bill of Materials is welcome in my book.

Check it out! Partsim