Accidentally trashed SD card (OS X)

Short of outsourcing, long of free: SpinRite.

https://www.grc.com/sr/spinrite.htm

This appears to be a transcript of Gibson chatting with Leo Laport and it describes using SpinRite on an SD Card:

https://www.grc.com/sn/sn-358.txt

It also mentions that reading an SD card is not quite like reading a hard disk.

I've used Recuva successfully on SD cards several times. Be careful where you download it from so you don't get malware. Also during the installation process you'll probably need to untick the additional software options. I would probably run it directly from a USB drive.

Thanks for the suggestions. Since the card was FAT32 I was able to install testdisk from brew and use that to recover all of the files. Phew.

PhotoRec

http://www.cgsecurity.org/wiki/PhotoRec