Wii U Usb Helper Android Here

: Allows users to download games directly on an Android device and then "push" or upload them to a homebrewed Wii U console via the Wii U USB Helper Transfer Tool Title Database

If you don't want to use a PC, you can try directly on a modded Wii U console to download games, though you would still need to transfer them to your Android device later. wii u usb helper android