If you have ever accidentally deleted files or deleted a file and then wished you had it back, you need an app like Undelete for Root Users. As the name says, you do need root access to be able to use the app and it was recently updated with new features. The Undelete app is a free download, but to get full functionality does require an in-app purchase.
The free version of the app is only able to restore image files. The paid upgraded version can restore other types of files as well. The latest version of the app is able to recover deleted files from any volume on an internal partition or SD card. You can recover documents, video, music, binaries, and pictures on the full version of the app. The saved files can be restored directly to Dropbox and Google Drive.
The update brings support for 64-bit operating systems, an improved MP4 parser, and fixes for crashes from user reports. A new journal scanner has been added and an improved MP3 parser as well. A new scan for individual file extensions has been added. Some fixes for major issues have been integrated into the latest version of the app including a freeze fix, various crash fixes, and an old filter icon has been restored.
This app is unable to restore all files even in the unlocked version. Some of the files may be too damaged for restore, but if the files are undamaged, you can get them all back. Again, the app does require root/superuser permissions and you have to modify the OS on your device to use the app.
SOURCE: Google Play