The Pokéwalker is a device that was released alongside Pokémon HeartGold and SoulSilver. It allows players to transfer a Pokémon from their game cartridge into the Pokéwalker, and then walk around with the Pokémon in order to raise its happiness and earn Watts. Once the player has earned enough Watts, they can use them to catch wild Pokémon or find items.
Unfortunately, due to technical reasons, the Pokéwalker is no longer compatible with newer versions of Pokémon games. This means that if you have a newer Pokémon game, such asPokémon X and Y or Pokémon Omega Ruby and Alpha Sapphire, you will not be able to use yourPokéwalker. However, if you still have a copy ofPokémon HeartGold or SoulSilver, then you can continue to use your Pokéwalker as normal.