Titanium Backup is a powerful backup tool for Android devices that requires root access. It has over 25 million users and supports 32+ languages. The app allows users to backup, restore, and freeze their apps, data, and Market links. This includes protected and system apps, as well as external data on the SD card. Users can perform 0-click batch and scheduled backups without closing any apps. They can also move apps and app data to and from the SD card, browse app data, and access detailed information about apps from the Market.

The app offers even more features with the paid PRO key. These include 0-click batch restores, multiple backups per app, backup and restore of SMS, MMS, calls, bookmarks, and Wi-Fi AP as XML, multi-user app data, apps freezer, and sync to and from Dropbox, Box, and Google Drive. Other features include a TB Web Server for downloading and uploading backups as a single ZIP file on a computer, converting user apps to system apps, integrating system app updates into the ROM, encryption, Market Doctor for relinking apps to the Market, and a "Destroy all Market links" feature. The app also offers various performance enhancements, such as Hypershell speed, backing up apps without closing them, creating custom update.zip files containing apps and data, and restoring individual apps and data from non-root ADB, CWM, and TWRP backups.

It is important to note that the app requires certain permissions, such as internet access for accessing the Market, Dropbox, and ChangeLog, and accounts access for accessing the Market. The developers advise against using modified versions of Titanium Backup, as they can cause various problems in the future.