The function that the built-in Calendar app lacks – ShareCal - Easy Calendar Event Sharing via Email, iMessage and AirDrop Review

The only way you can share a calendar event with the built-in Calendar app is through invitations. Sometimes you want to just share an event without it being a full-blown invitation. This app connects to the same calendars and lets you do that. As a bonus, this app lets you “queue up” multiple events and share them in a single e-mail. I do wish, however, that this app would allow you to share events through text messages and iMessages instead of only through e-mail.
Review by Robert Fisher on ShareCal - Easy Calendar Event Sharing via Email, iMessage and AirDrop.