Apple refers to "subscribing" to calendars and makes it very easy to not only allow your desktop Calendar app to view GoToList calendars, but all of your "iCloud" devices may do it through a single process described here. If you use an Apple Calendar on your computer, we strongly suggest you follow this process rather than setting it up on each of your devices.
From the GoToList app (sign in at www.goto-list.com), copy the unique url for the calendar you wish to view by opening the Calendar of interest, select "Actions > Subscribe" and click on the "Copy Link".
On your Mac computer, then open the Apple Calendar app and select "File > New Calendar Subscription" from the main menu. Paste the GoToList url into the field by holding "Command-V" keys and click the "Subscribe" button.
In the following screen,
- Enter a Name for the Calendar (usually you should use the List name)
- Keep the location as "iCloud" if you can as that will make it available on all of your iCloud devices (iPhone, iPad, etc).
- Change the "auto-refresh" to "Every Hour" or more often depending on your needs, and click OK.
You should now see the GoToList calendar in your Mac's calendar app and any other iCloud device attached to that account.
Your calendars will be automatically updated whenever there are changes to the primary GoToList calendar.