Data Missing After iOS or iPhone/iPad Upgrade/Restore

This seems to be an unfortunate side-effect of the upgrade process for third party apps, sometimes not all the data is loaded, or the device and application become available for use before the restoration of your data from an iCloud or iTunes backup is complete (major upgrades to iOS use the iCloud/iTunes restore process to bring your data back after the upgrade). The good news is that usually all you need to do is perform an additional restore. Apple has good instructions available for restoring from iCloud and iTunes. Information on taking a backup is also available.