Livewire is described as 'sophisticated software package for designing and simulating electronic circuits' and is an app in the Education & Reference category. There are more than 25 alternatives to Livewire for a variety of platforms, including Windows, Mac, Linux, Online / Web-based and Android. The best alternative is KiCad, which is both free and Open Source. Other great apps like Livewire are Fritzing (Paid, Open Source), QUCS (Free, Open Source), LibrePCB (Free, Open Source) and Autodesk EAGLE (Free Personal).
The Quite Universal Circuit Simulator (QUCS) is an integrated circuit simulator allowing the simulation and graphical presentation of results of large-signal, small-signal and noise behavior in circuits.
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.