Use core_message_get_messages to display list of notifications

This issue only needs to be tested in 1 device. If you don't have one already, create a course with 2 enrolled users: a student and a teacher. Login as the teacher. Add an assignment to the course. While creating, enable 'Notifications > Notify graders about submissions setting'. Go to Preferences > Notification preferences. Make sure "Assignment notifications" is disabled for Web . Login as the student and submit the assignment. As admin, run the cron to send the assignment notifications. In web as teacher, open the notifications menu at the top. Check that you do NOT see a notification about the submitted assignment. In the app, login as teacher and go to the notifications tab. Check that you see a notification about the submitted assignment.