I have a love/hate relationship with Flexibits' Fantastical. There is absolutely no faster, easier, more human way to enter appointments into your calendar. And because of that, my calendar -- previously a wasteland -- is now bristling with appointments. My only saving grace was that Fantastical was bound to my Mac, and I couldn't use it when I was out and about, with only an iPhone in my pocket. But with Fantastical's terrible awesomeness coming to the iPhone, I can now fill up my calendar faster, easier, and more humanly than ever before on the go, and no matter where I am. I'm organized now. I have no excuse left not to be. Dagnabit.
If you haven't used Fantastical before, it fixes almost everything that's wrong with Apple's built-in, kludgy Calendar app. Instead of tapping and filling in appointment or event details, you just type in natural language phrases and Fantastical parses it and creates the entry. "Lunch with Leanna at 8", "movie on Saturday with Georgia", "call on the 28th with Phil and Kevin", Fantastical takes it all in and makes it just work. Like Siri, but with a type-driven, instead of voice-driven, interface. If you want to edit all the fine details you can do that as well, of course. But the point is you don't have to until you want to.
The iPhone version makes great use of the smaller (than Mac) display, presenting 2 perpendicular scroll views. On the top is a horizontally scrolling date list. Tap a date, go to that date. Tap the top bar, go to today's date. On the bottom is a list view of all your events. Tap an event, get the details to that event.
And Flexibits absolutely, positively, gloriously nailed the bi-directional scrolling in a way that just feels perfect. Scroll the dates and the events change, scroll the events and the dates change. Flick and they both whizz by in perfect synchronicity, always slowing and stopping on a full event break.
If you want to see a month view, just pull down on the dates and either peak at it, or keep pulling to switch completely. If you want to peak or go back, just pull down again. (It's a state-toggle gesture, not a window shade analog.)
To add an appointment, tap the + button and, as described above, simply write what you want to add. Appointments get added to your default calendar, but you can also tap Show Details and edit everything in a more traditional manner, including changing the calendar, adding repetitions, making events all-day, and more. If you're using the iCloud calendar or a Google calendar, or any calendar with sync, the event will propagate across your devices just as you'd expect.
There are a lot of other great little touches in Fantastical for iPhone as well, like how words animate and playfully saunter down from the entry field to the calendar. , and how, as you type times and dates, the calendar flips, also playfully, to the right page. No part of the user experience has been left unpolished or anything less than delightful.
With the iPhone 5, iPhone 4S, and iPod touch 5, you can also use the built in iOS voice dictation to get a Siri-like effect by simply saying your natural-language event phrase. That means Fantastical can actually handle natural language through speech or type, which is a huge advantage. (I've wanted Siri to handle text queries via Spotlight for a while now for just that reason -- sometimes it's easier to talk, sometimes quite inopportune.)
I've been using Fantastical for iPhone for a while now, and I haven't touched Apple's Calendar app since. It's been reverse Sherlocked -- Flexibits saw an opportunity where the built-in app wasn't meeting a need, and provided a compelling alternative.
That doesn't mean it's for everybody, however. To be as focused as it is, Fantastical leaves out some things as well. There's no landscape mode, no week view, and no a lot of other features that other calendar apps absolutely nail. For me, speed of entry and speed of lookup are the most essential element of an iPhone calendar app, and that's Fantastical's forte. For other users and use cases, different priorities will apply.
Like I said at the start, if you want the absolute fastest, easiest, most human way to get appointments into your calendar, you'll want Fantastical for iPhone.