SteamChecker is a Firefox extension designed to streamline the shopping experience for gamers. It effectively tracks owned and wishlisted games on Steam while browsing Humble Bundle. By graying out owned games in bundles and highlighting wishlisted titles, users can avoid purchasing duplicates and seize great deals on desired games. This tool is particularly useful for those who frequently explore Humble Bundle's offerings, ensuring a more informed purchasing decision.

To use SteamChecker, users simply install the extension, input their 64-bit SteamID or profile name, and the extension takes care of the rest. It automatically updates with the latest changes from Humble Bundle, ensuring accurate tracking of game ownership. Despite its limitations with certain DLC collections, SteamChecker remains a valuable asset for any avid gamer looking to optimize their game purchases.