Chips and wires can be deleted by "backspace" or "delete" buttons if you point wire or select chip. What about "power off", i also didnt found it. It would be helpful function, for example i tried to count fibonacci sequence by two 16 bit registers and one 32 bit summator and i wish to power it off and restart calculation and show it to my brother (it is adorable to reconnect 16*4=64 times to restart experiment). Also i wish, that developer will add zooming for better experience.