Godot addon with a Cubic Bézier Curve Resource and Controls for visualizing and editing them.
Curves start and end points are fixed to (0, 0) and (1, 1), storing only the two control points. Editor Control have one handle for each control point, similar to https://cubic-bezier.com.
Predefined curves for common easing functions are also available, with values taken from https://easings.net/.
Available at the Asset Library.
Live preview a sample scene in this link.