We have the circuit lab tool which is pretty ok for linear circuits, but it would be nice to have a proper logic simulator too.
I have no idea what was involved or how much time it took to get circuit lab ported in, but I'm guessing one of the on-line logic simulator folks, something like Simulator.IO or better, would not mind helping port their system here for the visibility.
I realize you can do logic in circuit lab, but the functionality and usability is very limited.