QUCS is described as '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' and is an app in the Education & Reference category. There are more than 25 alternatives to QUCS for a variety of platforms, including Windows, Linux, Mac, Online / Web-based and Android. The best alternative is Circuit Simulator, which is both free and Open Source. Other great apps like QUCS are LTspice (Free), Ktechlab (Free, Open Source), OrCAD (All Products) (Paid) and Circuit Simulator (CircuitJS1) (Free, Open Source).
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.
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.
It is a circuit simulator on a virtual breadboard. it supports virtual components like microcontrollers, TTL, graphical and alphanumerical LCDs and others in addition to virtual instruments and certainly the basic components (resistors, capacitors..).