There are two ways to realize it:
1.Turn on Display In-Game under Temperature tab.
2.Tick the check-box “Display real-time temperature and FPS value in full-screen games” in In-Game of Settings. You can also choose the position to display In-Game.
What if I can’t find my game in GameBox?
If Smart Game Booster fails to detect your game automatically, you can add it manually by dragging its shortcut into GameBox or clicking Add button.