Shader Pack Lite for Godot 4: 2 free 2D shaders
Two free 2D shaders for Godot 4.4+: a sprite outline and a pixelate effect.
Shader Pack Lite for Godot 4: 2 free 2D shaders is free on itch.io. Made by Nam Trung Studio (Godot 4 add-ons).

Two free 2D shaders for Godot 4.4+: a sprite outline and a pixelate effect. Drop a .gdshader on any sprite and tweak the settings in the Inspector. No art files, no dependencies.
What is inside
Outline: coloured outline with adjustable width
Pixelate: adjustable pixel size
Short README with a code example
Free for unlimited games
Honest note
These are the same two files that ship in the full pack. Tested on desktop (macOS, Godot 4.7). Not tested on mobile or web.
License
Use in unlimited games. Do not resell or share the shaders themselves.