We just deployed the option to run the app as one of our users. When you’re in the database view (Data Tab -> App Data section), you can see a new column when you’re viewing the list of users. Clicking on ‘Run as →’ will let you run the app as the user you picked, without having to enter this password (or ask for it, which is never great).
This is especially useful when you want to debug privacy stuff, etc. Please not that until you log out (or you run as somebody else), you’ll be logged in as this user.