Slotkeeper

Copy Slotkeeper into an email thread and it handles the back-and-forth: proposing times that respect your preferences, reading replies in plain language, rescheduling when someone cancels and sending the invite. It knows that you prefer mornings for calls and never book over a lunch block, because you told it once.

Executives, recruiters and consultants who schedule with people outside their company use it in place of booking links, which some recipients find impersonal. It works with Google and Microsoft calendars across time zones. Requests involving more than five people or several rooms are slower, and it occasionally asks you to clarify vague replies such as "sometime after the launch".