User interface and simplicity to book appointments (it's easy)

I loved the way we could no longer have duplicate appointments during the same timeline. Something sensible from an appointment management software.

These days, we're all scheduling way more online meetings than ever before. Using Appoint.ly cuts out a few steps in that process, allowing for external audiences to view your schedule and pick a timeslot. Internal colleagues could, of course, use it as well, but we use Outlook for scheduling our internal meetings so there's no need to use this, too. So it's basically a way of letting external people access your Outlook calendar so they can find mutually convenient times to schedule meetings, without a lot of back-and-forth conversation required to do so.