Hi there!
You can sync your devices by using cloud based calendars, like iCloud or google. myCal PRO can read and write to those calendars, so adding or editing events on one device will sync with the other.
I personally use iCloud based calendars, you can convert your local calendars to iCloud quite easily.
Take a look at this web page for more information:
http://www.apple.com/uk/icloud/setup/ios.htmlRegards
John