AutoSteamSpy от ickmiester

Visit any Steam store page, and the Steamspy stats for that same application will be automatically queried. As soon as the data about the game is returned, a context menu will be added containing all of the summary stats.

Please note that the data from Steamspy is the latest collection estimates. For a more accurate view, you should check the full Steamspy page to view averages, as polling can sometimes have a variance (listed).