A basic C# application that serves as sort of assistant to Steam with the games, where it's possible to use Steam Overlay, but Steam itself fails to hook into on its own. What it does, is it's monitoring processes running and if a specified process is found running, it runs GameOverlayUI.exe with process's ID as argument to make the overlay hook into application.
SuiMachine/Steam-Overlay-Hooking-Helper
A basic C# application designed to help hook Steam Overlay into games.
C#Unlicense