I recently developed a new Google Chrome extension called Steam Hover.
The extension will show Steam app details with mouse hover on a Steam link. Below is a screenshot as an example.
I developed the extension initially as a way to more quickly browse /r/gamedeals. For future plans I intend to look into indicating if the user already owns a game as well.
More details about the extension as well as a button to add to Chrome may be found on the extension’s GitHub page: