1) In a web browser on your computer, go to http://calendar.google.com and create a calendar that you'd like to sync with (ie: SWA or Flight Schedule, etc..)
2) Download Google Calendar from the Play Store (https://play.google.com/store/apps/details?id=com.google.android.calendar&hl=en) and make sure you can see the calendar you just created within the Google Calendar app on your phone.
3) Launch CrewBuddy and go to settings; Under the "Calendar" heading select "ON" for "Sync Trips to Android Calendar"
4) Click on "Calendar" and select the Google calendar you created in step 1.
5) Hit OK and Sync.