Titanium Backup is a great and useful app and also a must have the app on a rooted android phone. It is a great tool used to backup your apps and either user or system apps.You need to backup your apps because if you want to flash a new ROM you will need to backup your apps in other not to lose all your data and saved games.
It can be used to create profiles to enable you to use two or more social media The pro version can be used to freeze any unwanted or bloatware apps on your phone & RAM consuming app. It can schedule future backups.
And can be used to convert a user app to system app. It can convert your backup to flashable.zip to flash through any recovery You can even use to clear Dalvik cache without even booting to recovery.