I made a new app today to automatically lock my computer after a defined time period. It's useful for if you want your computer to auto-login after booting up, but don't want to leave it wide open to tampering. From the readme:

Timed Locker is a basic tool to use if you want to perform a delayed lock of your computer for any reason. Its original creation was for me to put in my system startup to lock my computer after a certain amount of time unless I typed in the correct password. I did this so that I can auto-login to my PC on startup so that things like Outlook start and process my email. I like to start my computer via Wake on LAN before I get into the office, but I do not like to leave my workstation logged in unattended. This solved the issue for me.

Check out the app page for more details.