Data Recovery EX is 100% safe and effective for data recovery software.

Data Recovery 101
Immediately stop saving to the affected drive. When you notice that you've accidentally delete or overwritten a file, do not save anything else on that hard drive. Avoid running programs as well. Whenever new data is written to the drive, there's a chance that it could be set to override the data from the old file. Not saving anything increases the chances that you'll be able to recover the file.
You should recover the file as soon as possible.
Go to Disk Utility.app's menu. File > New > Disk Image from "YOUR_DISK_NAME".
Choose "read-write" as your image format. Set encryption to "none".
Save your disk image and open it use Data Recovery EX.app.

Key Features:
• Recover deleted or damaged files from Mac hard drive.
• Recover deleted or damaged files from storage devices: USB drive, SD Card.
• Any media file type supported.
• Disk formats supported: HFS+, FAT16/32, NTFS, NTFS5, EXT2, EXT3, EXT4.
• Scan and analysis on formatted drive.