Undelete is a data recovery app for Android phones that needs root permission to operate, it lets you recover data erased from your internal Android phone memory and external SD cards, it only supports the FAT format, this is the most used format in smartphone memory cards. The app can recover any kind of data, images, audio, video, text, zip, etc. It only works if the erased data has not been overwritten yet, if you saved a new file on the empty space after erasing the data or securely wiped the file using a data shredding app, the files won’t be recovered.
After installing this app you will be asked about the memory card where you want to recover data from, click on “Scan storage” and the app will start scanning the selected memory card (internal or external), the scan shows the file path, size and name, to recover the file simply tap on “Restore“, if you have many files on the recovery window you can use the search feature. Recovered files are placed on the directory they resided in before being erased.
Undelete is a good free alternative to Hexamob Recovery PRO, another Android phone undelete app, but I don’t know if Undelete will still be free once it comes out of beta stage (trial), if the app is successful there are plans to add support for EXT4 formatted cards, a filesystem often used in Linux. The developer claims to succesfully have tested this undelete app on Incredible S, Nexus S, Xoom, Transformer, Sensation, Galaxy S I/II, Galaxy Ace, Desire. On Tegra devices it only supports external SD memory cards.
Tip: If you are using an external SD memory card for data storage, you should be able to plug it into your computer and use standard Windows data recovery tools.