"There may be cases where you may want to be reminded about all of the notifications you have on the S7 and S7 Edge. You can set this up by going to Settings > Accessibility > Notification reminder.
The Notification reminder menu allows you to set alerts via vibration or sound when there are unread notifications. The Reminder interval lets you set the number of minutes that you want to be reminded about the notification. And the apps that you want to receive notifications from are selectable in the menu."