Not to hijack this thread or anything... but calendaring is something that matters a lot to me since my days' schedules have a habit of being very fragmented. I came up with a modestly clever solution using Android Wear, to display my free/busy time on the face of the watch. I'm giving it away free / open source.

http://www.cs.rice.edu/~dwallach/calwatch/

At that link, you'll find pointers to the Google Play Store, to Github, and to a one-hour talk I wrote about it for my sophomore CS class.