Gateway is an easy-to-use logic circuit simulator intended to help teach the basics of digital logic. Its development was inspired by a lack of free, user-friendly software of its kind. It is meant as a simpler alternative to applications like Logisim. A compiled version can downloaded from its website. Here are some of its features:
Create custom components and specify their layout based on the postion of inputs and outputs in your design.
Gateway is designed with performance in mind, allowing users to build complicated circuits without worrying about lag, even on slower machines.
Easily view and change the properties of individual components, and add comments to keep track of how your circuit works.
Gateway has all of the quality of life features you would expect, like copy/paste and undo/redo. New components are inserted simply by clicking where you want them to appear, and wires are created by dragging from one connection to another. One current limitation is that wires cannot be reshaped, and this will be improved upon in the future.