Like the Android recovery app . Androiddatarecovery app , Android rescuer ,Mobiledic ,Tunesbro and more .they are good at recovering deleted data from Android phone ,
I usually keep the data on my computer, i think it's safe for the data to say,of course, I need to transfer the data to my computer in advance ,so I can backup it
If you just want to delete everything from Android SD card , you'd better use eraser tool to do ,
Once you use it to erase your Android SD card , all of the data save on the SD card can be completely deleted ,