CyberChef - A web app for encryption, encoding, compression, and data analysis; curated by GCHQ on GitHub.
Mouse Test - Simple JavaScript-based mouse click test for troubleshooting faulty mouse switches
List of free software - high-quality, professional-grade software offered at no cost
List of useful tools - utilities that inevitably find their way onto most machines I use
Windows Update Assistant - Force Windows 10 to update to the latest version
Ninite - Install/update multiple common programs with one utility