miRack started as a fork of VCV Rack - a Eurorack-style modular software synthesiser. The goal was to fix the performance issues, add multithreaded audio processing (which VCV Rack didn't have at that time), and ultimately to make it usable on single-board computers like Raspberry Pi and ASUS Tinker Board. This version is available at mi-rack/Rack GitHub repo, along with a web version that was made available later using Emscripten technology. I even tried prototyping some hardware that would be based on Tinker Board, have a touch screen and some number of encoder knobs to be mapped to virtual knobs on screen, but that project didn't go very well.
However it was clear that a touch screen is much better suited for dragging virtual cables between modules and for using knobs and other controls than a mouse, and also that there's no need to build hardware when there are iPads with big screens and fast CPUs.
Unfortunately, due to a mistake during early performance tests (which made them show performance on iPad worse than on Tinker Board), I abandoned that idea. Only recently I fixed the error, redone the tests and started porting miRack to iOS.
Now the work is done, and miRack will soon be available on the App Store.