Qucs is an integrated circuit simulator which means you are able to setup a circuit with a graphical user interface (GUI) and simulate the large-signal, small-signal and noise behaviour of the circuit. After that simulation has finished you can view the simulation results on a presentation page or window.
This should be in the repository because there are only few great circuit simulators for Linux-based system. And correct if I'm wrong, there is no circuit simulator package yet in the repository, right?
Since Solus is Linux-based, there is a large number in the users that have professions inclined to circuits.
Official website: http://qucs.sourceforge.net/
Source tarballs: https://sourceforge.net/projects/qucs/files/qucs/