Rotom is caused by the secret key event which requires you to use one of the items. When you join a trade room, it reverts back and the item is placed back in the laboratory. What would happen if you gave it to this app, and traded it to another game? You would lose the item forever. Skymin is caused by the flower event. Skymin can only be used during the day, and it reverts back at night. What would happen in the Wii when it became night? I doubt forms will be allowed, but I hope they find a way.