iOS: Fantastical 2 for iPad and iPhone were both updated today to include a bunch of new iOS 8-specific features. It now comes with interactive notifications and a today widget.
You can now interact with notifications to snooze them when they pop up, pull up Fantastical in your Notification Center, and create new events from a share menu. The Notification Center widget's particularly nice because you get a full month view instead of just your events for the day. Both apps are also on sale right now for 40 per cent off.