Similar to the suggestion above, I have a ‘Release’ data type.
The release has a date, title, and description which are displayed in the popup.
When Do a search for Release (date > Current User’s lastReleaseDate):first item is not empty, show the popup and Make changes to Current User (set lastReleaseDate to the Current date/time) .
FYI, same approach can apply to tracking whether user has accepted the most recent version of periodically updated policies, like terms of service and privacy.