I'll share this simulation I did to experiment with visualization on Kotlin:
https://github.com/TomasVolker/kbody-problem. It's using OpenRNDR (
https://openrndr.org/) a Kotlin library for graphics, aimed for creative coding. It is very well done and I believe it will be very useful for developing a Kotlin scientific visualization library. The project is a straightforward euler solver for the n-body problem, basically computing the trajectories of celestial bodies. It doesn't scale (it's using an all against all force calculation on each step) but I think it's a good example of a quick prototype on these kind of problems.