uFlysoft Data Recovery is a commercial data recovery app. It can be used to recover files that you have accidentally erased from your Mac, or files that were accidentally lost. As you may know, when you delete a file, you are not erasing it completely. The operating system only removes the logical link to that file. This application can scan your hard drives and volumes and find files that are still on your hard drive but your Mac won't see.
The first window that you will see will show a list of all the volumes currently mounted on your Mac. In my case, it showed my Mac's internal hard drive and an external 1TB hard drive. Here, you select the hard drive that you want to scan and the process starts. The speed of the scan will depend on the type and speed of the drive and on how much data is on it. Scanning my 1TB hard drive was going to take a couple of hours. You can stop the scan at any time and recover files that were found up to that point. Sadly, there aren't any options to filter the type of files that you want to look for, which would make the process much faster.
The scan results window shows the files that were found sorted into filetype. You can preview most files, but the app wasn't able to preview some video files in my testing.