I use Image Rescue 4.
Beware, some of the freeware ones do garblefile names, do not recognize raw or mov files, and don't always do a good recovery job. They should not affect the card itself, so if they do not do the job, try a different one. After going thru several crappy freeware ones, I finally paid for a good one.
Note: I'm not referring to the Transcend program, i've not used it.