Micro-Cap is described as 'Integrated schematic editor and simulator' and is a Circuit Simulator in the Education & Reference category. There are more than 25 alternatives to Micro-Cap 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 Micro-Cap are Circuit JS (Free, 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 JS.
KTechLab is an IDE for microcontrollers and electronics. It supports circuit simulation, program development for microcontrollers and simulating the programmed microcontroller together with its application circuit.