To add the school's calendar to your Google Calendar, make sure you are logged into your account and then click on the "+Google Calendar" above or click HERE.
For iOS Calendar:
1. Copy this link:
2. On your iPhone or iPad go to Settings > Accounts & Passwords > Add Account > Other.
3. Tap on Add Subscribed Calendar.
4. In the Server section, paste that ICS link you copied.
5. Choose a Description.
6. Tap the Use SSL switch and hit the Save button.