Google Calendar
Available now
What it reads. Read-only access to your calendar events. For each event I keep the title, start and end time, whether it is all-day, recurring or cancelled, whether you organized it, and how many guests were invited or declined. Never guest names or email addresses, descriptions, locations or attachments.
Why. To count appointments, cancellations and no-shows, and tell customer visits apart from everything else on your calendar.
