After trying out several calender apps, i thought i found a reasonable solution in Pocket Informant. However, this app has the tendency to lock itself up in either landscape or portrait mode. This happens often. It locks up and you can't rotate it anymore. You need to do a complete reboot to get it unlocked. Could this be a bug?
Another problem I've encounter is with the syncing. Apparently it only syncs with google when you launch the app. Eventhough there is a setting where you can let it autosync at a desired interval, it will fetch events only when you launch it. This means that when you create an event in google calender and don't open Pocket Informant, you will not receive an alarm or anything. This seems to be a problem with all other calender apps except for the stock ipad calender which is terrible.