QDX Health ID is to share results of your immunity.
They dropped immunity a while back, presumably when they figured out that would pose legal challenges as a back-to-work tool under the ADA. Now it's just most recent test status which is kind of pointless unless you're getting tested ever other day.
"Family, friends, 3rd parties....it can be shared via social media."
Are you going to share your status or a link to your HealthID App status on Facebook? Not very secure in keeping your information private. Would also be easy to fake a "Green" status on facebook.
The point of the APP is you can securely share your status with others from the App.