The Steam Achievement Guide is a subscription-based extension for Firefox that significantly enhances the Steam gaming experience. It displays detailed achievement guides directly on game pages, providing essential insights such as difficulty levels, required playthroughs, estimated completion times, and information on missable achievements. Users can access guide details for up to 20 games on their wishlist for free, making it a useful tool for gamers looking to optimize their gameplay.

For subscribers, the extension offers exclusive features like hover access, which allows users to instantly view achievement guides by simply hovering over game titles. Additionally, subscribers can unlock unlimited guide views for all games on their wishlist. The extension also provides a special Discord role, allowing subscribers to stand out within the gaming community. Overall, this extension serves as a valuable resource for gamers aiming to achieve 100% completion in their favorite titles.