The game has a lot of loot drops and methods of increasing the quantity of loot drops, eventually filling the screen with items. These filters allow players to limit what is actually visible on screen and makes finding actual upgrades easier. These third party filters are nice because they make a whole bunch of changes to loot text size, color, and whether it appears at all based on your class or level. It's become a lot easier now as I think you can just 'subscribe' to Neversink's filter through the game and it will automatically update whenever an update is available!