FreeBusy eliminates the back-and-forth needed to find out when business partners or friends are available for a meeting
FreeBusy makes it easy to share your availability even if you have multiple calendars for work or person, even if they are across different services like Gmail, Google Apps, Outlook, Exchange, Office 365, iCloud, Yahoo, Zimbra. FreeBusy works with all calendar systems, whether personal or corporate, and across organizational boundaries. All your calendars can be linked to show a unified view of your availability. FreeBusy doesn't show the details of your calendar events, just the fact that there's an event scheduled at a particular time. You can choose to share only certain days of the week or only certain times of the day. FreeBusy is a free service.