Android 4.3, is the fastest and smoothest version of Android yet. And it improves on the simplicity and beauty of Android 4.0, and introduces a new Google search experience on Android.
First, you must back up your ZTE Grand X information.
Google has your back. Go to Settings > Privacy, and make sure that “Back up my settings” and “Automatic restore” are checked off. Go to Settings > Accounts and sync, open your Gmail account, and check off all options. With these settings in place, your contacts, system settings, apps, calendar, and e-mail will be restored whenever you set up a new Android phone with that same Gmail account.
Google hasn’t implemented a native photo backup service yet, so look to third-party apps to safeguard your photos. You might want to consolidate your mobile photos with those you already have stored in a cloud service. For instance, Photobucket Mobile will automatically upload newly snapped photos in the background to your Photobucket account. Flickr Companion and Picasa Tool are also free apps that allow mobile uploading but don’t do so automatically