SimpleGizmoDisplay is a simple utility file for displaying in-editor gizmos in Unity.
You can drop the component on to any GameObject, select your parameters, and it does the rest for you. It’s possible to have the component multiple times on the same object to create more complex gizmo displays (e.g. you could have an icon displayed on a character with on SimpleGizmoDisplay, but a line coming out of the character, pointing toward something, with another SimpleGizmoDisplay).
All parameters are accessible publicly, so it’s very easy to script for.
C# code here