WUP Installer GX2 is a homebrew application used to install Wii U games, updates, and DLC directly to your console's NAND (internal storage) or an external USB drive. Requirements for Installation
A Modded Wii U: Your console must have custom firmware (CFW) installed. Aroma or Tiramisu are the modern, recommended environments. WUP Installer GX2: The homebrew app placed on your SD card.
The WUP Installer Patched was a tool developed by the homebrew community that allowed users to download and install games on their Wii U consoles. While it provided a means for users to access games not available through official channels, it also raised concerns about piracy, security risks, and warranty/support implications.