Galaxy Note 3 can remind you of your unread notifications by specifying Reminder Interval. The interval can be set from every 3minutes to every 1hour. Set Notification Reminder on Galaxy Note 3 by doing as follows:
1. Open Settings, then go to Device tab
2. Tap Accessibility.
3. Under Vision settings, tap Notification Reminder and make sure it is enabled
4. Now you can set the reminder interval. Available options are: 3, 5, 10, 30, 60 minutes