You can set student alerts based on specific criteria. Alerts are sent to the Alerts page.
Note: Once the Course Announcements alert has been enabled, any announcements created thereafter will display in the Alerts tab.
To enable a toggle alert , tap the toggle so it shifts to the right.
You can also be notified of alerts when an assignment is above or below a certain percentage. To enter the percentage, tap the numbers next to the assignment criteria  and enter a percentage.
If necessary, you can disable the alert at a later time by re-opening the alert and clearing the percentage.