Updated July 11, 2014:
ForeFlight Mobile 6.2.1 is now available on the App Store and will resolve the app close issue. If you updated to version 6.2 and your user waypoints are missing, please contact us at firstname.lastname@example.org for instructions on how to restore them. If you deleted and reinstalled the app as a workaround, it isn’t possible to recover the user waypoints. We apologize for this happening and we appreciate your patience while we fixed it. If you experience any further issue with 6.2.1, please contact us immediately at email@example.com.
Earlier today we released version 6.2 which includes support for our new data sync capability. Some customers are experiencing an app close after updating to 6.2, which is a result of a data migration process when run against large numbers of recent routes and plates.
We jumped on a fix as soon as the issue was detected. A fix for customers experiencing this issue is in version 6.2.1, which is submitted to App Store and pending review. As a workaround, customers can delete and reinstall the app if they need to bypass the issue.