While no official app exists, resourceful users have found partial solutions. Some use Windows emulators like Winlator or ExaGear to run the original USB Helper on high-end Android devices. Others rely on remote desktop apps to control a PC running USB Helper from their phone. More recently, projects like NUSspli (for the Wii U console itself) or NUT (a Python-based downloader) offer cross-platform alternatives, but none match the all-in-one simplicity of USB Helper on Android.
Once you've gathered the necessary hardware and software, follow these steps to set up Wii U USB Helper on your Android device: wii u usb helper android