Free-to-use app icons, document icons, and Pixelmator templates
Officially used in Amethyst, BarBox, BTTV for Safari, IINA, Karabiner-Elements, LuLu, Mochi Diffusion, OnlySwitch, Stats, Swift Quit, and TomatoBar.
The document icons that I've reworked are for IINA, Keka, VSCode/VSCodium & CodeRunner ― or any code editor (in this case I advice to choose the CodeRunner one, since it's more complete).
You can also find my app icons on macOSicons.