To follow an iCal feed on an iOS device, the basic procedure is to acquire the iCal feed URL from the website, and then add it to the saved feeds on your device.
Getting an iCal link
To find the iCal URL for a particular calendar, select the "Feeds" icon in Composer or the "Calendar Export" icon in Page Manager and go to iCal Feed.
In the "Calendar Feeds" window, select "Get Standard iCal URL" from the menu on the green "ICAL" button.
If you perform this step on your iOS device, then you can long-press this URL to "Select All" and copy it to the clipboard. If you cannot perform this step on your device, obtain the link on your computer, email or text the URL to your mobile device, and then copy the URL on your device.
In either case, you should end up with the iCal feed URL on your clipboard. (If you email the feed URL to yourself, you may be able to simply tap on the link to subscribe to the calendar feed; if that works, skip the steps below.)
Adding an iCal subscription to your device
Once you have copied the feed URL, add it to your mobile device in the "Settings" menu to automatically track any updates to the calendar. To add a calendar feed to your iOS device, start in the Settings app.
Go to the menu item labeled "Accounts and Passwords."
On the list of account types, select "Add Account" at the bottom.
Then select "Other" followed by "Add Subscribed Calendar."
Paste in the iCal feed URL that you previously saved to your clipboard in the field marked "Server" and select "Next."
Your device will verify the feed URL and add it to your calendar. Subsequently, new events will automatically populate in the Calendar app.