Yeah, I looked into that. There doesn't seem to be a way to have a "hidden" extension whose URL isn't public, but which can be downloaded without signing into a Google account.

That sucks for people in my network who are being kind enough to test my software.

Instead of just messaging them on Facebook/Twitter/Skype/Email/SMS/iMessage/Linkedin with a URL, I need to find out their Google account and add it to a dashboard and they need to be logged in before they download.