This App is not developed or supported anymore, I considered it my abandonware, but if you have an old Mac with macOS 7.5 to 9 feel free to download and use it for free, you can try it on a 68k emulator like SheepShaver
Okidoki Guard is a nice and simple App designed to password-protect your Mac. To install simply launch the app, define your password, and reboot your mac. Okidoki moves itself to Startup items in the System Folder. For uninstall Okidoki just click in the "Uninstall" button in the setup window. Okidoki Guard also has a cool feature called Maxi-Proteccion which creates a Log file "OkiLog" (located in Preferences Folder) with the date and time of every password error, Maxi-Proteccion also shut down the computer if a user fails 3 times in the password prompt screen, and if someone attempt force to quit Okidoki Guard.
Compatible with Mac OS Classic System 7 - 8 and 9.
You can download Okidoki Guard here: OKIDOKI GUARD (ver 2.2)
Register Okidoki Guard with this Serial Number: 24066189
YES, Okidoki Guard is COMPLETELY FREE
You are protected by this License:
Copyright (c) Mario Gajardo Tassara