I just found the smartphone calendar app I've been wanting for a long time. It's called Mynd (version 4.11) and what's unique and compelling about the app is that it's smart, in fact way smarter than any calendar app I've seen.
Mynd links to your calendars and beyond just gussying up the display (which is as much as many other calendar apps manage to do and what Mynd also does rather elegantly) is to mine your schedule along with other resources and generate useful data, such as warning that you have a meeting across town in 30 minutes and given the current traffic conditions you need to leave in the next 5 minutes (it also inserts an entry for your travel time in your calendar).
Then, when you click on the calendar entry for the meeting, Mynd shows you the attendees (if you've enabled it, Mynd grabs their LinkedIn profiles and clicking on an attendee's image shows their data). Mynd also displays the weather, any related notes you have in Evernote (if you've enabled this service), and a map of the destination. Click on the map and your preferred map app is launched with the route selected. Running late? Press the "Late" button on the meeting screen and a text will be sent each of the attendees. Mynd even learns your route to work.
Mynd is free, (currently available only for iOS), and is perhaps the most useful calendar app I've come across (so far). Highly recommended, Mynd gets a rating of 5 out of 5.
<img src="http://appcenter.evernote.com/images/made/assets/img/apps/mynd/mynd-icon_140_141_c1.png" />[<em>Updated 02/05/14 to correct which platforms Mynd is available on.</em>]