Nexus Backup - bibanon/android-development-codex GitHub Wiki
In a perfect world, (or for some, an unwanted future), your app data would also be backed up to Google's servers. There is, in fact, prewritten code that allows developers to do so. But since this is a new thing, most apps don't use it.
There are two methods; the Carbon app, and the official ADB backup method. Use Carbon if you'd prefer an easier method and per-app backup/restore. Use the official ADB backup if you want to restore a ton of app data, all at once.
One issue with Carbon is that if you don't have root, you'll need to manually reinstall every app from the Play Store before restoring app data. If you have a ton of apps, we suggest using the Official ADB Backup instead.
Backup
Note that this backup method is only guaranteed to work on vanilla Android systems, such as Nexus or AOSP devices. Otherwise, use caution and check Google to see if your phone has problems with it.
This backup method is a complete, one-step app backup and restore, whereas Carbon requires the user to reinstall the app from the Play Store each time.
TitaniumBackup is the best method of backing up and restoring your app data. If you are jumping from custom ROM to ROM, or you just want to keep your game saves safe, you need this app.
TitaniumBackup requires you to press Install for each app you want to backup, unfortunately. If you want to batch restore all apps, you will have to buy the PRO key.