The stock Google Calendar has been updated allowing you to change the default color for the calendar and also have specific events represented by a specific color. You can have your appointments in blue and your girlfriend's appointments in red, for example. Or you can have all of your doctor's appointments coded in yellow. The new color coding will also allow you to separate your business appointments from personal ones.
The new windows used to select the time and date of an event will also now allow you to set up a recurring event. The update also offers a searchable time zone feature. Check out the slideshow below for screenshots from the updated app, which can be found at the Google Play
Screenshots from the updated Google Calendar app