A calendar app that I have been playing around with on my iPad is Sunrise. Overall it is a nice app and looks great. Well Sunrise has been updated to include Android devices and now a desktop or web interface.
I am still exploring the app and new web interface but I like it even more! Having a web interface is a great asset; I am at my desk a lot during the day so this makes it really easy for me to keep up with appointments and add new ones.
The app allows you to add material from Facebook, LinkedIn (just to name a couple), and of course your Google Calendar. In the iOS app you can add “interesting calendars” such as the World Cup match schedule. I have not found that ability in the Android or web interface yet.
From the developer:
On desktop, Sunrise will help you stay organized by combining all the information you need in one place. The desktop app is fast, beautiful and brings everything you love about Sunrise to your desktop. It takes 5 seconds to get started.
Sunrise for Android brings the best calendar to the most popular mobile platform. We’ve worked really hard to make an amazing user-experience for Android and leverage all the great features of Android, like widget and rich notifications.
For iOS users, you can get it from iTunes.
Overall Sunrise is a beautiful app and with it being free there is no reason NOT to try it.