Binaries for FCND-Simulator. Download the binary for your platform from the releases tab.
Issues regarding the simulator should be posted here https://github.com/udacity/fcnd-issue-reports.
The simulator has some controls you might be interested in:
The Linux binary may not have executable permission depending on your OS. To change this navigate to the binary file in the terminal and type the following command:
# executable permissions
chmod +x name_of_file