Electronic circuit simulator.
Simple environment to run and debug firmware for AVR 8-bit microprocessors.
Able to run arduino firmware.
Internally this program uses the open source Simavr AVR Processor Simulator (https://github.com/buserror/simavr) and wraps all its functions in a GUI shell. Setups for firmware debugging scenarios can be created dynamically. Able to run 16MHz MCU with decent set of external parts in real time.