Widget Settings / Notification log
To see your notification history, just tap on the newly-created widget. You will see every notification you’ve received, along with a timestamp.
To expand the information, tap on an individual notification. Depending on the type of notification, you might be able to see a brief snippet of information from the alert.
I was very surprised to find that this log of all notifications is virtually cluttered with hidden Splendid notifications about which the user had no idea (It doesn't matter if your are using Wide color gamut or not). What is this weird system hack and why is it? Can anyone explain it?