Yes! In fact CrewBuddy will sync with any calendar you have set up on your iPhone or iPad. 

iCal is just the name of the calendar app on the iPhone/iPad.  iCal can display any calendar - iCloud, Google, Yahoo!, Exchange. CrewBuddy can access any of those calendars through iCal.

Make sure the account is set up on your device
Go to your iPhone/iPad Settings
Scroll down and tap on Mail, Contacts, Calendars
Here you can either add the account you want or verify Calendars is turned ON.

Enable Calendar Syncing in CrewBuddy
In CrewBuddy go to Settings
Scroll down and tap on Sync Trips to iCal
Turn Sync Trips to iCal to ON
Then select which calendar you would like CrewBuddy to sync to.
Now go back and sync your trips with CWA!