Disk Drill requires Mac OS X 10.8.5 or newer to run and perform memory card recovery on Mac (there are older versions of Disk Drill available for older versions of Mac OS X). Once you are ready to recover deleted files on SD card on Mac, download the app and install it in your Applications folder, launch it and follow these steps to complete memory card recovery with your Mac.
Unique features of Disk Drill are Recovery Vault and Guaranteed Recovery. First option serves to create "maps" for Disk Drill to help it locate deleted files. Second option will create an invisible copy of each file moved to Trash. Protected files are recovered in the first place.
Try Deep Scan of Disk Drill when everything seems desperate and there is hardly any file structure left. Whatever filesystem you have, Disk Drill will go through every bit of it applying its knowledge of file signatures and seeking for the known ones. Once it finds sought signatures recovering files like XLS, DOC, AVI, MP4, JPG, and others goes pretty fast.