Something interesting that I can no longer prove since the app has been since removed. I saw this app and looked into what other apps were published by "Internal Beta Account". I found an app called "Ursal ____" (I don't remember the exact name) which I attempted to install. To my surprise it worked. I went to the app and opened it. It was immediately familiar as it was the Microsoft Health app just masked with a different icon and name. This leads me to believe that this "author" is in fact an official Microsoft account used for nothing more than the name implies, beta testing.