Tracking GameObjects with Overlay

I am making a game where some gameobjects are just too small to see and I want to make a overlay,so it still can be seen where the gameobject is. How can i determine where the overlay should be on the screen.
Thx, lix

Create an overlay and position it on the screen. Then you can add an offset (vector3 e.g.).

The function you need to get the screen position is Camera.WorldToScreenPoint