If you're looking to build or enhance a similar feature, focus on these core elements:
: Use the game engine's drawing functions to project a circle or cross on the wall/sky to guide the player's aim.
: Integration with a library of established "pro" lineups for various maps like Mirage, Inferno, or Dust 2. Creating a "Solid Feature" Inspired by This Script
: Real-time visual arcs showing exactly where a grenade will land before you throw it.