Titanium Backup is a root app that allows you to back up your apps and all their data.
Link2SD is a root app that moves all files an app stores in internal storage to a special partition on SD card, and creates symlinks into the internal storage in place of the original files.
Does Titanium Backup work with Link2SD? That is, does it correctly back up the files that the symlinks point to, or does it instead end up backing up just the symlinks?