SaveFileConverter is a website that allows you to convert save files for various retro consoles including the Wii. It also includes a tool to help troubleshoot save files, and links to other save file converters.
The tool processes Wii VC saves into files that can be directly loaded into an emulator or written to a cartridge.
The main goal of this project is to allow people to use the various save files that can be found around the Internet.
The tool can convert Wii Virtual Console, Retron 5, GameShark (GBA), GameShark SP (GBA), and Action Replay (GBA) saves.
If the user is having trouble with a particular save file (particularly GBA files, which tend to be problematic), they can specify the save along with a known working save obtained from the emulator or cartridge they're trying to use. The tool will then compare the padding in the two files, and attempt to make the problematic save look more like the known working one.