Outlook is the most popular email/calendar app on the planet, and offers an easy way to subscribe to GoToList's calendars so they appear directly in Outlook.
First, from your computer login to your GoToList account (www.goto-list.com) and copy the unique Calendar url by viewing the calendar you want, selecting "Actions > Subscribe" and clicking on "Copy Link".
Open Outlook on your computer, click "File > Account Settings > Account Settings."
On the "Internet Calendars" tab, click "New".
Paste the GoToList calendar url by pressing CRTL+V or CMD+V, and click "Add".
In the "Folder Name" box, type the name of the calendar you want to appear (usually the GoToList list name works best) and click "OK".
Outlook will automatically update the calendar for you.