Steam : Game finder
Steam : Game Finder allows you to find which multiplayer games are shared within a group of steam users
What is Steam : Game finder?
Stats
Chrome-Stats Rank
Other platforms
Summary
Simply add a user using its nickname, or if it doesn't work, paste a link to her/his community profile page (for example : https://steamcommunity.com/profiles/76561197970839736 or https://steamcommunity.com/id/nebukam/ ) and you're good to go from there !
Note that a user data is stored on your computer for later use : if after some time you find that some games recently purchased are missing, make sure to click the "refresh profiles" button :)
User reviews
Safety
Risk impact
Steam : Game finder is risky to use as it requires a number of sensitive permissions that can potentially harm your browser and steal your data. Exercise caution when installing this add-on. Review carefully before installing. We recommend that you only install Steam : Game finder if you trust the publisher.
Risk likelihood
Steam : Game finder has earned a fairly good reputation and likely can be trusted.