The Pokéwalker is a pedometer device specifically for use with Pokémon HeartGold and SoulSilver that is able to interact with the games in various manners. It was released in Japan on September 12, 2009 bundled with every copy of Pokémon HeartGold and SoulSilver, and then later released with every localized copy of the games. The accessory has a Poké Ball design with a small monochrome LCD screen and three functioning buttons. The Pokéwalker supports infrared signals allowing players to interact within a short range with a game card of Pokémon HeartGold or SoulSilver while slotted in the Nintendo DS, or with another Pokéwalker.
The system records every time a step is taken, and the daily step count influences which wild Pokémon and items will appear. The player can transfer a Pokémon to the Pokéwalker from either HeartGold or SoulSilver, which gains experience for each step. Like the Pokémon Pikachu and Pokémon Pikachu 2 GS, the Pokéwalker uses a currency known as "Watts" (shortened to w); every 20 st