Lack of Updates is Mozilla's failure Rated 5 out of 5 stars
If you expand the "Version Information" further down and click on "See complete version history" (https://addons.mozilla.org/en-US/firefox/addon/status-4-evar/versions/), you'll see that there have been newer versions of this add-on, all of which don't show because Mozilla hasn't reviewed them.
The latest version officially adds FF 29 support. I just installed that one, and my status bar is back under FF 29.0 Linux.
The author did everything right. Mozilla fucked up.