eSim is described as '(previously known as Oscad / FreeEDA) is an open source EDA tool for circuit design, simulation, analysis and PCB design. It is an integrated tool built using open source software such as KiCad and' and is an app in the Education & Reference category. There are more than 25 alternatives to eSim for Windows, Linux, Mac, Online / Web-based and Android. The best alternative is KiCad, which is both free and Open Source. Other great apps like eSim are Fritzing (Paid, Open Source), LibrePCB (Free, Open Source), Autodesk EAGLE (Free Personal) and EasyEDA (Free).
This electronic circuit simulator is highly interactive giving the feeling of playing with real components. It's very helpful for experimentation and visualization. It's a desktop version of the Circuit Simulator.
The gEDA project has produced and continues working on a full GPL'd suite and toolkit of Electronic Design Automation tools. These tools are used for electrical circuit design, schematic capture, simulation, prototyping, and production.