My favorite calendar App for iOS just received an update today. Flexibits released Fantastical 2. The update brings a new look and feel for iOS 7 and adds integration with iOS reminders and better natural language parsing. This was an insta-buy for me but if you need convincing, Federico Viticci at MacStories has an excellent review, as does Dan Frakes at Macworld. There's also a cute video on the Flexibits site.
Fantastical 2 is $2.99 from the App Store and discounted for a limited-time launch special. Grab it now.