I can play them in dolphin emulator but i can't find a program that extracts files from a single wad file.
Like a wiiware wad file contains text + graphics + sounds + music + other files. It maybe is embedded or compressed.
All the files after extraction maybe is in unknown file formats. The file extension and headers may vary from wad to wad. Different wiiware games have different files in their wad file with unknown file extensions and headers.